All Your History Are Belong To Us S01 E22 Valve Part 6: Beyond the Crowbar... And Beyond

From Half-Life to Left 4 Dead 2, Valve has been one of the trailblazers of the video game industry. In this sixth and final episode of our retrospective, watch how Valve finally left their Half-Life franchise behind to pursue a brand-new IP, Left 4 Dead, and then created amazement and controversy with its swift follow-up, Left 4 Dead 2.