Half-Life 2: Episode Two is a 2007 first-person shooter game developed and published by Valve. Following Episode One (2006), it is the second of two shorter episodic games that continue the story of Half-Life 2 (2004). Players control Gordon Freeman, who travels through the mountains surrounding City 17 to a resistance base with his ally Alyx Vance. Like previous games in the series, Episode Two combines shooting, puzzle-solving and narrative elements, but adds expansive environments and less linear sequences.

Valve Corporation, also known as Valve Software, is an American video game developer, publisher, and digital distribution company headquartered in Bellevue, Washington. It is the developer of the software distribution platform Steam and the game franchises Half-Life, Counter-Strike, Portal, Day of Defeat, Team Fortress, Left 4 Dead, and Dota.