Massive Valve leak unearths 12TB of unreleased builds for games like Portal 2, alongside a whiff of Half-Life 2: Episode 3

A massive archive of games and unreleased builds uploaded to Steam from 2003 to 2013 has leaked online, and it includes never-before-seen versions of Portal 2 and many other games, alongside materials that could be related to the Half-Life 2: Episode Three that never saw the light of day. The 12TB leak was spotted by GabeFollower earlier this week, who says it features "internal builds and game assets" that stretch over the course of a decade. The materials include in-development builds of classic Valve games - Portal 2, Left 4 Dead, and Counter-Strike: Global Offensive - alongside materials related to unreleased games, such as the Portal prequel called F-Stop and "potentially" information on Half-Life 2: Episode Three. This is 100% Valve's fault," YouTuber Scolcer tweets online.