Undue Alarm

Introduction

A flashback of Dr. Breen appears, repeating his words to Freeman:

"Tell me, Dr. Freeman, if you can. You have destroyed so much. What is it, exactly, that you have created? Can you name even one thing? I thought not."

It is followed by a vision of the Citadel's portal explosion freezing in time; Alyx being saved from it by a group of Vortigaunts; the G-Man visiting Gordon in the stasis, but being interrupted by a group of Vortigaunts, who transport Freeman away; and finally, Dog digging Freeman from under the rubble, to Alyx's surprise and relief.

From here, the player obtains the Gravity Gun from Dog and can fully control Gordon.

Maps

ep1_citadel_00 - the start, getting into the Citadel.
ep1_citadel_01 - teaching the player Roller Mine reprogramming, the Advisor Pods chamber, super-charging the Gravity Gun.
ep1_citadel_02 - fighting off numerous Soldiers, dealing with Energy Orb puzzles.
ep1_citadel_02b - the big lift with falling debris hazard.

Architecture

The first map of the chapter begins among the completely devastated buildings at the foot of the Citadel. Gordon and Alyx soon enter the Citadel itself, discovering in the process that it is severely damaged inside, with fires burning, lights flickering or shut off completely, spontaneous explosions...

The Citadel interior is still composed of the same blue metal and dark stone tiles, but in the reddish, dull lighting they seem almost black. There are new damaged models of Combine panels and struts, bent, partially melted, blackened by fire.

Combine equipment can be seen detached from walls, torn apart by energy bursts, on fire. Twisted metal panels and props litter the corridors, create obstacles to be cleared out with the Gravity Gun. Forcefield bridges can flicker or require being powered, commonly by using Combine Energy Balls.

Environment

The color scheme of the environment has changed since Our Benefactors and Dark Energy; cold blue tones and sterile surfaces are replaced with predominantly orange hues, soot and ash.

This chapter serves as a partial revisit of Our Benefactors, and shares numerous elements with it. For example, Prisoner Pods can be seen moving along the rails (some of which terminate abruptly, sending the pod falling into abyss), as well as forcefield tubes with Combine Energy Balls inside, Combine Bridges, and Confiscation Fields. In fact, one of them is used to play out the same scenario as in Half-Life 2 - taking away the Gravity Gun, only to super-charge it.

The soundscapes reflect the extensive damage as well, with the Citadel PA talking in a slower, more strained tone, disharmonous droning, and the sound of alarms. On the outside, the soundscape includes deep humming comming from the vortex above the Citadel, hits of thunder, screeching of falling debris.

NPC's

Set almost entirely within the Citadel, the chapter includes several Combine units, such as soldiers, Stalkers, striders, Dropships and Advisors (the last three used passively, in scripted scenes; however, this doesn't have to be the case). The player needs to occasionally utilise Roller Mines, which Alyx can reprogram, to neutralize otherwise unreachable targets.

The Stalkers in Episode One are given the ability to burn out Combine Energy Balls from their receptacles, disrupting the power (done via map logic, the Stalker targetting an npc_bullseye). This plays a role as an environment obstacle/puzzle, as the player needs to find the way to eliminate the Stalker factor in order to progress.

Trivia

The name of the chapter comes from Dr. Kleiner's line of dialogue,

"Oh dear, Eli, I'm sorry, but...surely there's no need for undue alarm? Alyx is well out of harm's way by now."

At the beginning of the game, there is a crashed rotating pod that was used in Dark Energy for ascending the final chamber.

Later in the chapter, in ep1_citadel_02, Combine Soldiers can be observed placed inside memory replacement devices along one of Citadel's halls.

Despite showing the flashback pertaining to the end of Half-Life 2, the game begins several days after it.[1]

Reference

Exterior space in Undue Alarm, showcasing Combine debris, falling ash, and the sun just above the skyline.
Interior space of the Citadel, showcasing different lighting and surface colors than those of Our Benefactors.
Ditto.
Interior space, with obvious extensive damage.
Ditto, with Combine equipment malfunctioning.
Ditto.
Ditto.
Stalker operators in the Citadel.
A Combine Energy Ball puzzle, where the player needs to direct a ball into the receptacle to power the bridge.
Another version of the puzzle, the player has to kill the Stalker in order to solve the puzzle.
The Advisor Pods chamber, a space with extended vertical visibility and different appearance detail from most of the Citadel.
The lift at the end of the chapter, mirroring Gordon's ascent in Our Benefactors.
The crashed rotating pod, recycled from Dark Energy.
The memory replacement devices with Combine Soldiers inside.