A gigantic 12-terabyte archive from Valve's old Steam2 content servers has leaked online, containing internal development builds spanning from 2003 to 2013. The trove includes a July 2009 build of Portal 2 with unused sequences and beta menus, along with assets from F-Stop, the canceled Portal prequel. There's also a playable 2008 build of Left 4 Dead and early Counter-Strike: Global Offensive content.

The most talked-about find is a "Weaponizer" model appearing in the Portal 2 files, long rumored to be a concept weapon from the canceled Half-Life 2: Episode Three. The model has surfaced before, but never inside an actual game build, so its presence here is of some significance. However, it may simply have been repurposed as an unrelated placeholder asset.

Contrary to how it may appear at first, the leak wasn't the result of a hack. It comes from an old, publicly accessible Steam2 endpoint that Valve apparently never took offline after migrating to Steam Pipe in 2013. Valve hasn't commented on this leak, and given the size of the archive, it will likely take the community days or weeks to fully sort through everything inside it.