April 8, 2005 - After weeks of simmering speculation, the latest edition of PC Gamer UK has unveiled Aftermath, the expansion pack to Half-Life 2, said to feature Alyx and Dog in a more high-profile role, slated for release this summer, and under development by Valve. It's not entirely clear if Gordon will be the main character, but it sounds like Alyx won't be, either. Reportedly, Alyx has a pistol in the SDK that can be upgraded to a sniper rifle and submachine gun.
Aftermath will take place after the events in Half-Life 2, as the citadel you crippled will launch into space, and you and Alyx will escape from City 17. Without the barriers put up by the alien invaders, creatures previously unable to enter will be able to roam freely, making your escape that much more difficult.
It also sounds as though the expansion pack may be distributed through Steam rather than through Vivendi, their current publisher, because of the time-consuming mastering, duplication, and distribution. "The reason we're able to do this, and the reason it's so exciting, is because of Steam," Valve designer Robin Harper says in the PC Gamer article. "If we're doing this without Steam, we'd have to put it in a box. We'd have to start figuring out shelf space over a year beforehand."