View source for Half-Life 2 map reference

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In the order commonly played, here is every HL2 map:

=Day 1=
Arriving in City 17 to just starting a journey towards Nova Prospekt.

==[[Point Insertion]]==
Arriving in City 17 all the way to Alyx and the player first meeting.

===d1_trainstation_01===
The map with [[Gman]]'s intro monologue. From there, it goes through everything from arriving at the train station to encountering [[Barney]], and then leaving the interrogation room and ending with the first freely openable door in the game.

<gallery>
Hl2 d1 trainstation 01 gman.png|Gman speaking to Gordon before dropping him in City 17.
Hl2 d1 trainstation 01 trainyard.png|The outside.
Hl2 d1 trainstation 01 inside.png|Inside the station.
</gallery>

===d1_trainstation_02===
Starts with the well-known "pick up that can" cop. Goes through an old building of some sort then out into a plaza. From there it goes into an alley and a playground area with two citizens talking about [[Civil Protection]]. It ends with the player heading into a building.

<gallery>
Hl2 d1 trainstation 02 cancop.png|"Pick up that can".
Hl2 d1 trainstation 02 foodbuilding.png
Hl2 d1 trainstation 02 plaza.png|The plaza Barney spoke of before.
Hl2 d1 trainstation 02 alleyandcourtyard.png
</gallery>

===d1_trainstation_03===
The insides of an apartment complex. Takes a very long and specific path with lots of detail and dialogue to give players more insight into how life is in [[City 17]]. About half-way through, the player is detected as someone who should not be there and becomes a target of [[Civil Protection]] and is chased.

<gallery>
Hl2 d1 trainstation 03 overview.png
Hl2 d1 trainstation 03 doorcrash.png|CP's raiding an apartment.
</gallery>

===d1_trainstation_04===
Starts with continuing the chase from the previous map through rooftops. [[Gordon]] is apprehended and trapped defenseless by four metrocops. He is quickly saved by [[Alyx Vance]], their first encounter. Alyx escorts the player over to [[Dr. Kleiner]]'s lab, passing through a secret door with a poster of [[Breen]] on it.

<gallery>
Hl2 d1 trainstation 04 outside.png
Hl2 d1 trainstation 04 alyxcloseup.png|The player's first view of Alyx.
Hl2 d1 trainstation 04 secretdoor.png|The secret door.
</gallery>

=="A Red Letter Day"==
Kleiner and Gordon first meeting, to fleeing City 17.

===d1_trainstation_05===
Alyx continues taking Gordon to Kleiner's lab, passing through another secret door. Barney comes a short time later, Gordon gets his suit. The teleporter glitch incident occurs, the [[Combine]] becomes aware of Freeman's presence, and he begins to flee.

<gallery>
Hl2 d1 trainstation 05 secretdoor.png|Secret door to Kleiner's lab.
Hl2 d1 trainstation 05 kleinerlab.png|Kleiner's lab.
Hl2 d1 trainstation 05 teleporter.png|Teleporter room.
</gallery>

===d1_trainstation_06===
Gordon continues fleeing, but is stopped when his path is blocked by wood planks. Barney comes a few seconds later, telling him to go through the canals. Barney also gives him the first weapon in the game, the crowbar. Gordon continues exiting City 17. This map goes through the trainyard area first seen in <code>d1_trainstation_01</code>.

<gallery>
Hl2 d1 trainstation 06 barneycrowbar.png|Barney giving the crowbar. In the distance are the wood planks.
Hl2 d1 trainstation 06 trainyard.png|Trainyard. Compare with the second screenshot from the first map.
</gallery>

==[[Route Kanal]]==
The first part of Gordon's journey through the City 17 canals. Starts with two cops hurting two citizens, and ends with getting a boat.

===d1_canals_01===
Starts with two cops assaulting a citizen, as another citizen watches in fear. Gordon kills both and picks up the second weapon in the game, the pistol. The player fights on through a railway and comes across a boxcar. Inside, a human and a vortigaunt help the player keep going. Gman is briefly seen on a tv that they are both looking at.

<gallery>
Hl2 d1 canals 01 policeassault.png|Police hurting a citizen.
Hl2 d1 canals 01 railroad.png|The railroad followed through. Due to the forcefields in the way, the player has to detour around them.
Hl2 d1 canals 01 boxcar.png|Inside the boxcar.
</gallery>

===d1_canals_01a===
The player sees a crow fly right into a barnacle tongue and be eaten. This is the first time in Half-Life 2 a barnacle is seen.

Ahead is Station 12, currently being raided by Civil Protection. One citizen escapes the initial massacre and tries to plead with Gordon to help him, but before Gordon can do anything, the citizen is shot dead by a cop. In the lower bunker of Station 12, an unknown woman tries to radio the station. Station 8 gets on the line, saying they heard the Station 12 raid, refugees are coming in from Station 9, and stations are being raided. The man from Station 8 is interrupted by something before he can finish speaking. The woman speaks again, saying that [[manhacks]] are being deployed.

On the roof of Station 12, two metrocops man a mounted gun. If the player kills them and takes over, they can kill many enemies approaching easily. If they stay too long, a Combine APC will come and shoot the gun with rockets until it breaks.

Further along, a citizen calls for the player and reassures them that there are other stations who can help. Metrocops attempt multiple times to kill the player with explosive oil drums.

<gallery>
Hl2 d1 canals 01a barnacle.png|Crow caught by barnacle.
Hl2 d1 canals 01a massacre.png|Station 12 members being shot. (It's hard to see them as they are shot.)
Hl2 d1 canals 01a helpme.png|Escapee citizen.
Hl2 d1 canals 01a mountedgun.png|The mounted gun on the roof of Station 12.
Hl2 d1 canals 01a barreltrap.png|An attempt to kill Gordon with explosive barrels.
</gallery>

[[File:Hl2 d1 canals 02 puzzle.png|500px|thumb|right]]
===d1_canals_02===
This map starts with a physics puzzle. A large wood board rests on a cement pipe and 8 cinder blocks are scattered around the room. The player cannot proceed because the only way out is high up. There are many ways to get past this issue:
#Put the cinder blocks on one end of the wood board so that the end nearest to the exit is raised high enough for the player to jump to the exit. (This is the intended way.)
#Jump on the far end of the board to temporarily nudge it downward and jump off the near end as it raises.
#Stack the cinder blocks and use them as a makeshift ladder/steps.
#In the previous map (<code>d1_canals_01a</code>), before going off the slippery downward ramp at the end, try to jump across the gap to the exit platform.
#Load the map directly (or {{ent|restart}} in the console). You will spawn just past this physics puzzle.

After this puzzle, the player encounters a hunter chopper. It takes every opportunity to shoot at the player as they evade it.{{clr}}

===d1_canals_03===
The player encounters another station (11? The number is never stated) with a single person inside. Quickly, a group of manhacks crashes in and attacks. If the player does not attack the manhacks (sometimes just distracting them is enough) the citizen will be killed. This is the first time manhacks are seen. After going through many more areas, there is another small "puzzle" here. The player has to turn a valve to raise the water level in a room in order to pass through it.

<gallery>
Hl2 d1 canals 03 station.png
Hl2 d1 canals 03 puzzle.png
</gallery>

===d1_canals_05===
Gordon encounters what is evidently Station 6. Black Mesa East (possibly Alyx speaking?) radios this station to tell them to give Gordon the airboat. Before the player can reach the boat, they must pass through a small area currently being bombarded with headcrab canisters. After this, a citizen gives the airboat over to the player, and says to drive to nearby Station 7.

<gallery>
Hl2 d1 canals 05 station6.png|Station 6.
Hl2 d1 canals 05 canisters.png
Hl2 d1 canals 05 boat.png|Getting the boat.
</gallery>

====d1_canals_04====
This map was scrapped during development of hl2. {{todo|Find out more about it.}}

==[[Water Hazard]]==
The complete boat journey from the City 17 canals to Black Mesa East.

===d1_canals_06===
Station 7 is close to the start. The occupants of this station have been zombified by headcrabs, though. On the radio, a woman is heard attempting to reach Station 12 again. Ahead is another physics puzzle. Usually, the player will solve this by putting a few barrels under a ramp, so that they can jump across with the boat. They can also choose to just abandon the boat and go on foot. (good luck)

<gallery>
Hl2 d1 canals 06 station7.png|Station 7 from the river.
Hl2 d1 canals 06 puzzle.png|Ramp puzzle.
</gallery>

===d1_canals_07===
The player raids a Combine post and must destroy some explosive barrels to allow for a floodgate blocking their path to open. The enemy firepower increases as rocket-firing APCs are deployed more and more frequently.

<gallery>
Hl2 d1 canals 07 post.png|The post, from above.
Hl2 d1 canals 07 barrels.png|The player breaks the barrels, and the explosion breaks the wood holding the i-beams in place. The beams become a battering ram for the large gates.
</gallery>

===d1_canals_08===
The player raids another Combine post, this time a hunter-chopper is summoned to harass them. As the player drives off, the helicopter starts using bombs on the player for the first time.

<gallery>
Hl2 d1 canals 08 post.png
</gallery>

===d1_canals_09===
The helicopter continues chasing the boat. It mainly attacks by dropping more bombs on the player's path.

<gallery>
Hl2 d1 canals 09 bombs.png|Bombs being dropped.
</gallery>

===d1_canals_10===
Yet another chase map. The helicopter loses track of the player as they drive through a tunnel.

<gallery>
Hl2 d1 canals 10 tower.png|A chimney falls and interrupts the player's path.
</gallery>

===d1_canals_11===
The player encounters a rebel outpost. Here, a vortigaunt equips the airboat with a high-power gun, which is used to ward off the hunter-chopper for a while.

<gallery>
Hl2 d1 canals 11 vortgun.png|Vortigaunt welding gun.
</gallery>

===d1_canals_12===
Nothing too special about this map. It has lots of APCs and exploding barrels.

<gallery>
Hl2 d1 canals 12 apcs.png
</gallery>

===d1_canals_13===
The final encounter with a hunter-chopper, which is persistent and fights to the end. After this, the player reaches Black Mesa East.

<gallery>
Hl2 d1 canals 13 bullrush.png|Helicopter entering "bullrush" mode.
</gallery>

==[[Black Mesa East]]==
The lab that Eli Vance does stuff in. When the player is here, the lab is raided by the Combine.

===d1_eli_01===
Gordon enters the airlock and meets Mossman and Eli again. After a long expository sequence, Alyx takes Gordon over to the scrapyard.

<gallery>
Hl2 d1 eli 01 outside.png|Outside.
Hl2 d1 eli 01 airlock.png|Airlock.
Hl2 d1 eli 01 lab.png|Eli's lab.
Hl2 d1 eli 01 ravtunnel.png|Tunnel to Ravenholm.
</gallery>

===d1_eli_02===
Alyx gives Gordon the gravity gun, and the player learns how to use it here. Gordon meets Dog and they play fetch. The Combine comes and begins to raid the base. Everyone rushes inside. Alyx has to stay behind but Gordon escapes by going through the Ravenholm tunnel.

<gallery>
Hl2 d1 eli 02 scrapyard1.png|Scrapyard.
Hl2 d1 eli 02 scrapyard2.png|Scrapyard again.
Hl2 d1 eli 02 dog.png|Dog.
</gallery>

==[[We Don't Go To Ravenholm...]]==
Scary time with a monk guy and going around some mines, and ending up back in City 17, but not for long.

===d1_town_01===
The player enters Ravenholm. Father Grigori is first heard from a distance. At a certain point, Grigori is seen, helping the player fight off zombies. Most of the gameplay elements for the chapter are introduced here: the players uses blades, fire, and cars (crushing traps) to kill zombies.

<gallery>
Hl2 d1 town 01 courtyard.png
Hl2 d1 town 01 grigori.png|Grigori.
Hl2 d1 town 01 blade.png|A blade trap spinning.
Hl2 d1 town 01 fire1.png|Fire trap.
Hl2 d1 town 01 fire2.png|Fire trap.
Hl2 d1 town 01 crush.png|A car about to crush some zombies.
</gallery>

===d1_town_01a===
Basically a continuation of the last map. Killing more zombies in various ways.

<gallery>
Hl2 d1 town 01a explosions.png|A chain reaction of explosive barrels.
Hl2 d1 town 01a zombieline.png
</gallery>

===d1_town_02===
====First Part====
Fast zombies are encountered for the first time. Father Grigori gives the player a shotgun. Shortly after that, a poison zombie is also introduced. The player continues on into <code>d1_town_03</code>.

<gallery>
Hl2 d1 town 02 shotgun.png
</gallery>

====Second Part====
After coming back from <code>d1_town_03</code>, the player eventually ends up at the top of a building connected to where Grigori is by a cart. The player must defend from zombies while waiting for Grigori to send the cart over. Grigori and Gordon finally meet, and they begin to travel over to the Ravenholm mines.

<gallery>
Hl2 d1 town 02 cart.png
</gallery>

===d1_town_03===
The player reaches a street with constantly respawning zombies, which must be escaped by taking the higher ground on the rooftops. Grigori says to not go off-path. The exit of this map goes back to <code>d1_town_02</code>.

<gallery>
Hl2 d1 town 03 overview.png
</gallery>

===d1_town_02a===
Grigori and the player travel through a zombie-occupied graveyard. At the end, Grigori opens a gate so the player can continue on to the mines.

<gallery>
Hl2 d1 town 02a overview.png
</gallery>

===d1_town_04===
The Ravenholm mines, infested by a staggering number of headcrabs of each type. There is one last blade-cart-of-death thing at the end.

<gallery>
Hl2 d1 town 04 hole.png
Hl2 d1 town 04 bladecart.png|Blade minecart.
</gallery>

===d1_town_05===
The player re-enters City 17 at one edge. Snipers are guarding the train tracks here, probably looking for Gordon. They player moves on to encounter an active battle between rebel and Combine forces at Shorepoint. After all the enemies are defeated, one of the allies takes Gordon to the back. Alyx is there by radio signal. This is where the player finds out that Eli has been taken to Nova Prospekt. Alyx asks the rebels to lend Gordon the buggy.

<gallery>
Hl2 d1 town 05 sniper.png|Sniper shooting zombies.
Hl2 d1 town 05 alyx.png|Talking to Alyx.
</gallery>

=Day 2=
Starting the journey to Nova Prospekt, entering, and then teleporting out of the prison.

==[[Highway 17]]==
Majority of the path to Nova Prospekt that is driven.

===d2_coast_01===
Gordon gets in the buggy and is... "lifted" down to the ground by crane. The player drives on toward Nova Prospekt.

<gallery>
Hl2 d2 coast 01 pier1.png|Pier, with the car on it.
Hl2 d2 coast 01 pier2.png|Same pier, from the opposite angle.
Hl2 d2 coast 01 bridge.png|A gap which can only be crossed by using the buggy's turbo boost.
</gallery>

===d2_coast_03===
The player drives around a small bay and arrives at [[New Little Odessa]]. Here, Gordon meets [[Colonel Cubbage]], gets the rocket launcher, and takes down a gunship.

<gallery>
Hl2 d2 coast 03 bino1.png|A pair of binoculars, able to see across the bay to New Little Odessa.
Hl2 d2 coast 03 bino2.png|New Little Odessa from the binoculars.
Hl2 d2 coast 03 nlo.png|New Little Odessa in person.
</gallery>

===d2_coast_04===
The player arrives at another dock occupied by Combine soldiers. The player has to operate a magnetic crane to move their buggy to higher ground before continuing. Another gunship attack occurs as the player nears the top of the broken bridge.

<gallery>
Hl2 d2 coast 04 crane.png|Crane.
Hl2 d2 coast 04 bridge.png|A bridge that is crossed under, then over.
</gallery>

===d2_coast_05===
This is the first map to have rollermines that attack the player and can latch onto the buggy, severely affecting its handling. It also has a forcefield that blocks the buggy, which can only be disabled by disconnecting the source of power, an APC.

<gallery>
Hl2 d2 coast 05 rollermines.png|Rollermines popping up out of the ground.
Hl2 d2 coast 05 crossbow.png|The first crossbow in the game.
Hl2 d2 coast 05 apc.png|APC.
</gallery>

===d2_coast_07===
====First Part====
The player encounters another forcefield blocking them from crossing a bridge. There is one other route that can be used to progress; a door on the side of the bridge leading to <code>d2_coast_08</code>. This route has access to the power source for the forcefield.

<gallery>
Hl2 d2 coast 07 forcefield.png|Forcefield (faint appearance).
</gallery>

====Second Part====
Now that the forcefield is down, the player can continue driving on the top of the bridge, but not before backing up, because a train comes from the other way, and it will kill the player if they collide. From here, the drive continues on, into Sandtraps, the next chapter.

<gallery>
Hl2 d2 coast 07 train.png|Train!
</gallery>

===d2_coast_08===
The underside of the large bridge seen in <code>d2_coast_07</code>. The player goes completely across the bottom of the bridge here to reach a button that will turn off the forcefield in <code>d2_coast_07</code>. The player goes back the way they came after pressing this button, except now being harassed by a gunship.

<gallery>
Hl2 d2 coast 08 button.png|Room holding the button on the other side of the bridge.
</gallery>

====d2_coast_02====
This map was cut during development. {{todo|More information}}

====d2_coast_06====
This map was cut during development. {{todo|More information}}

==[[Sandtraps]]==
Ditching the car, getting bugbait, and arriving at Nova Prospekt.

===d2_coast_09===
A run-in with zombies inside a tunnel, then passing through some Combine-occupied buildings. Finally, a puzzle that requires the player to find two car batteries to power a gate.

<gallery>
Hl2 d2 coast 09 battery1.png
Hl2 d2 coast 09 battery2.png
Hl2 d2 coast 09 battery3.png
Hl2 d2 coast 09 battery4.png|Battery is under this tub.
Hl2 d2 coast 09 battery5.png|All batteries. 
</gallery>

===d2_coast_10===
The player arrives at Lighthouse Point. The car has to be ditched here. Combine soldiers invade in dropships. After that, a single gunship has to be taken down.

<gallery>
Hl2 d2 coast 10 lighthouse.png|The Lighthouse.
</gallery>

===d2_coast_11===
Gordon encounters Laszlo and his friend. Antlions kill Laszlo as he moves on the sand. Gordon continues carefully along (or recklessly if you do so desire) until encountering an antlion guard for the first time. After killing it, a vortigaunt extracts pheropods from the guard. The player is then taught how to use pheropod bugbait, then continues on toward Nova Prospekt.

<gallery>
Hl2 d2 coast 11 laszlo.png|Laszlo and friend.
Hl2 d2 coast 11 guard.png|Antlion guard.
Hl2 d2 coast 11 bugbait training.png|Area where player is taught to use bugbait.
</gallery>

===d2_coast_12===
With antlions now turned allies, the player fights a long way across a beach and cliffs to ultimately finally enter the perimeter of Nova Prospekt through a tunnel.

<gallery>
Hl2 d2 coast 12 overview1.png
Hl2 d2 coast 12 overview2.png
</gallery>

===d2_prison_01===
The first map in Nova Prospekt, taking place in a courtyard. The player must defeat two gunships before proceeding.

<gallery>
Hl2 d2 prison 01 hole.png|Path that opens after killing both gunships.
</gallery>

==[[Nova Prospekt]]==
The insides of the titular prison, until just before finding Alyx.

===d2_prison_02===
The first map inside the prison. Combine turrets are introduced for the first time, as well as the concept of knocking them over.

<gallery>
Hl2 d2 prison 02 antlion turret.png|Antlion knocking over turrets.
</gallery>

===d2_prison_03===
The player encounters another antlion guard. This map has lots and lots of enemies, and antlions are very helpful. There's also a room where it looks like soldiers were attempting to experiment on a vortigaunt. It is dead.

<gallery>
Hl2 d2 prison 03 vortigaunt.png|Vortigaunt bound to a chair. What's happening is not clear.
</gallery>

===d2_prison_04===
In this map, Breen is giving a berating speech about the current progress on capturing Gordon Freeman through a speaker. The main difficulties in this map are the height levels and multiple locked doors which are unlocked by pressing a button.

<gallery>
Hl2 d2 prison 04 screen.png|Breen is never seen, only heard. The sound seems to emanate from here
</gallery>

===d2_prison_05===
Fighting through more of the prison, starting from the laundry facilities. Following the laundry, there is a kitchen area that has a gas fire start inside it. In a cafeteria area, multiple combine soldiers fail to stop an antlion guard. At the end, combine-style moving walls attempt to crush the player.

<gallery>
Hl2 d2 prison 05 kitchenfire.png|Fire in the kitchen.
Hl2 d2 prison 05 moving walls.png|Moving walls.
</gallery>

==Entanglement==
Meeting Alyx, tracking down Eli, finding Mossman, and leaving Nova Prospekt.

===d2_prison_06===
First, Gordon and Alyx meet again. Alyx retrieves Eli's pod that he's been put inside and they communicate for a short time. Alyx stays behind to move Eli through the prison and to help Gordon find a way through the prison.

<gallery>
Hl2 d2 prison 06 alyx.png
Hl2 d2 prison 06 eli.png
</gallery>

===d2_prison_07===
This map consists of two [[arena (level design)|arenas]] designed for standoffs where the player must make use of Alyx-reprogrammed combine turrets to fend off waves of attacking soldiers. After the first standoff, it is discovered that Mossman is a traitor.

<gallery>
Hl2 d2 prison 07 mossman.png
</gallery>

===d2_prison_08===
Alyx and Gordon confront Mossman, and attempt to make her teleport them to Kleiner's lab. Mossman distracts Alyx, then teleports Eli and herself to an unknown, presumably Combine-controlled location. The final turret standoff then takes place, where Alyx and Gordon manage to hold off soldiers for long enough to teleport out of Nova Prospekt themselves. A soldier shoots an energy ball at the teleporter and the chamber starts crumbling just before they are teleported to Kleiner's lab.

<gallery>
Hl2 d2 prison 08 teleporter.png
</gallery>

=Day 3=
Continuing the Entanglement chapter. Goes through all of the remaining City 17 maps, into the Citadel, and to the end of the game.

==Entanglement (continued)==
===d3_c17_01===
Alyx and Gordon arrive at Kleiner's lab. Kleiner reveals that they had spent over one week's time teleporting from Nova Prospekt to City 17. An uprising has started since then, initiated by the destruction of Nova Prospekt. Gordon and Dog head out to find Barney.

<gallery>
Hl2 d3 c17 01 kleiner.png|Kleiner packing heat.
</gallery>

==Anticitizen One==
The first part of Gordon's push through war-torn City 17. Ends just before meeting up with Barney.

===d3_c17_02===
Dog fights Combine soldiers and an APC, then opens a gate for Gordon to go through before going back and fighting a dropship. There is a G-Man sighting with him briefly appearing on a tv screen. This map passes through some of the same areas that were in {{ent|d1_trainstation_03}} and {{ent|d1_trainstation_04}}.

<gallery>
Hl2 d3 c17 02 dog apc.png
</gallery>

===d3_c17_03===
The player finds their first rebel allies and learns how to command them to go places. At the plaza, a group of rebels is seen tearing down one of Breen's giant monitors. This map passes through most of the area from {{ent|d1_trainstation_02}}.

<gallery>
Hl2 d3 c17 03 monitor.png
</gallery>

===d3_c17_04===
This map introduces the player to hopper mines. Striders also make a re-appearance since the very beginning of the game, with both their turret and laser cannon seen in action.

<gallery>
Hl2 d3 c17 04 mine hole.png
</gallery>

===d3_c17_05===
The player and allies storm a barricade with metrocops, then go through an apartment complex.

<gallery>
Hl2 d3 c17 05 street.png
</gallery>

===d3_c17_06a===
This map takes place in an underground car tunnel. Eventually the player comes to an obstruction, where they must defend their area from Combine soldiers as a rebel on the other side plants explosives so that the player can come through. The player is then blocked by a door, which can be opened from the other side by going through a zombie-infested section of tunnel with toxic goo.

<gallery>
Hl2 d3 c17 06a medic.png
Hl2 d3 c17 06a goo.png
</gallery>

===d3_c17_06b===
Mostly notable only for its drawbridges. Lots of fighting.

<gallery>
Hl2 d3 c17 06b drawbridge.png
</gallery>

===d3_c17_07===
Alyx and Gordon reunite again. They fight their way down to a plaza with a power generator. The player guards Alyx while she disables the generator's shields, then the player disables it with the gravity gun. Alyx and Gordon then split up again as Alyx is captured and stormed off the to Citadel.

<gallery>
Hl2 d3 c17 07 plaza.png
</gallery>

===d3_c17_08===
The player fights through underground sewers and industrial structures including a tall warehouse where they have to ascend on a physics-affected suspended platform.

<gallery>
Hl2 d3 c17 08 lift.png|The platform, activated by a button.
</gallery>

====d3_c17_02_camera====
Appears to be identical to <code>d3_c17_02</code> except that the player spawns with no weapons or suit, and the scripted sequence with Dog starts automatically. This map is never entered at any point in regular gameplay. When the player tries to go to the next map, an error occurs because this map is not recognized by <code>d3_c17_03</code>. {{todo|Purpose?}}

=="Follow Freeman!"==
{{distinguish|Follow Freeman}} ''(The mod)''

Meeting up with Barney, raiding the Nexus building, and breaching the Citadel's walls.

===d3_c17_09===
Gordon kills Combine snipers to save Barney, then they continue onward.

<gallery>
Hl2 d3 c17 09 barney.png
</gallery>

===d3_c17_10a===
Barney and Gordon run to the Nexus building, dodging the [[Suppression Device]] along the way.

<gallery>
Hl2 d3 c17 10a nexus front.png
</gallery>

===d3_c17_10b===
Inside the Nexus building. Gordon and Barney fight through many soldiers as they locate three Combine power generators that must be turned off in any sequence before proceeding to the roof, at which point Barney stays behind. Uniquely to this map, there are ground turrets activated by laser tripwires. One of the large rooms features an ambush followed by a short standoff, and another one is a platforming puzzle where the player must avoid laser tripwires.

<gallery>
Hl2 d3 c17 10b floor turret.png|Ground turret.
Hl2 d3 c17 10b laser room.png|High-security laser room.
Hl2 d3 c17 10b generator.png|A generator.
</gallery>

===d3_c17_11===
The roof of the Nexus building. The suppression device is passed by (now inactive). A gunship must be defeated before proceeding.

<gallery>
Hl2 d3 c17 11 overview.png
</gallery>

===d3_c17_12===
Mostly the same area as <code>d3_c17_10a</code> but now an active warzone with rebels, soldiers and striders.

<gallery>
Hl2 d3 c17 12 nexus front.png
</gallery>

===d3_c17_12b===
A strider harasses the player as they try to maneuver through a destroyed building. Scanners also relay information about the player to the strider.

<gallery>
D3 c17 12b strider shot.png|Strider firing a cannon shot.
</gallery>

===d3_c17_13===
The player and rebels overtake a heavily destroyed building near the Citadel. Two striders have to be defeated before proceeding out of the building. Back on the streets, Gordon runs into Dog and Barney. Dog lifts part of the Citadel wall up, exposing a hole in the ground that opens access into the Citadel.

<gallery>
Hl2 d3 c17 13 overview.png
</gallery>

==Our Benefactors==
Entering the Citadel, to the final pod ride up to Breen's office.

===d3_citadel_01===
The player navigates a crumbling cliffside before jumping into the Citadel. They then get on a pod, because there is nowhere else to go. Taking the wrong pod results in inevitable death.

<gallery>
Hl2 d3 citadel 01 outside.png|Outside the Citadel.
Hl2 d3 citadel 01 pods.png|One path is better than the other...
</gallery>

===d3_citadel_02===
A breather. Just a scenic ride through the Citadel showing soldiers, stalkers, Combine synths and razor trains. At the end, the player is dropped in a weapon confiscation field.

<gallery>
Hl2 d3 citadel 02 ride1.png
Hl2 d3 citadel 02 ride2.png
Hl2 d3 citadel 02 ride3.png
</gallery>

===d3_citadel_03===
The weapon confiscation field vaporizes every weapon the player has, except the gravity gun, which becomes supercharged, able to grab and punt living soldiers. The player uses their new super weapon to fight through the Citadel.

<gallery>
Hl2 d3 citadel 03 weapons.png
</gallery>

===d3_citadel_04===
The player continues fighting through the Citadel. There is a long ride up on an exposed lift while soldiers attack from all sides. A strider is encountered at the very end, but defeating it is not required to progress.

<gallery>
Hl2 d3 citadel 04 lift.png|Lift.
Hl2 d3 citadel 04 strider.png|Strider.
</gallery>

===d3_citadel_05===
The player is forced to take another scenic pod ride, seeing more stalkers as well as two Combine synths unique to this map. This time, they are spotted by a camera which sends the player in a special pod path up to Breen's office.

<gallery>
Hl2 d3 citadel 05 camera.png|Camera.
Hl2 d3 citadel 05 gunships.png
Hl2 d3 citadel 05 highview.png
</gallery>

==Dark Energy==
The finale of the game.

===d3_breen_01===
Gordon is now captured along with Eli and Alyx. Mossman has a change of heart and saves them all for the moment. Breen tries to escape the Citadel by teleporting out. Gordon stops this, and sends the Citadel into a meltdown. Gman comes and takes Gordon out before the explosion, seemingly leaving Alyx.

<gallery>
Hl2 d3 breen 01 gravity gun.png
Hl2 d3 breen 01 advisor.png
Hl2 d3 breen 01 portal.png
</gallery>

Day 3 events continue into Half-Life 2: Episode One.