High Quality Content by WIKIPEDIA articles! Half-Life 2: Episode Two is the second episode in a series of sequels to the 2004 first-person shooter video game Half-Life 2. It was developed by Valve Corporation in tandem with Episode One, the first game in the series, and released in Q4 2007 via Valve`s Steam content distribution platform. The episode was released both separately and as a part of a bundled package, The Orange Box.