Episode One follows scientist Gordon Freeman and his companion Alyx Vance as they fight in humanity's continuing struggle against the transhuman race known as the Combine. When the story begins, Gordon wakes up outside the enemy's base of operations, the Citadel, after being left unconscious from the concluding events of Half-Life 2. During the course of the game, Gordon travels with Alyx as they attempt to evacuate the city.
JX6 says
Weakest part of HL2-trilogy... but it doesn't mean that it isn't good