First Strike is an action FPS set in the Half-Life 2 universe six days after the destruction of Nova Prospekt.
The player will travel back from the Lighthouse, where Gordon Freeman leaves his jeep, to City 17 in order to lead the uprising against the Combine. Matt (last name not decided yet), the main character who was a rebel leader before being captured by the Combine, was put on a train outbound from Nova Prospekt by Alyx shortly before Gordon meets up with Alyx. He is on the train heading away from Nova Prospekt when it explodes and causes his train crashes. (There is an intro movie that shows all of this.)
This storyline was put together by Colin Bissbort and Matt Webster (the main character is named after him) in mid January 2010.