Half-Life 2: Aftermath brings you the new adventures of Gordon Freeman and his able sidekick Alyx. At the end of Half-Life 2, you did critical damage to the Citadel. The whole place is going to go up, taking out City 17 and what's in its immediate radius. In this expansion, Gordon and Alyx are leading the flight from the city -- and getting up close and personal with some of the creatures and sights from the Half-Life 2.