Valve Software has reportedly acquired Star Filled Studios, a new development outfit located in San Francisco.
He is joined by Tod Semple, who also worked on Diablo 3 and Plants vs. Zombies, as well as Star Wars: The Force Unleashed at LucasArts.
Semple's LinkedIn profile states that Star Filled Studios "was acquired by Valve" in September, and that he's now "opening a new Valve office on the San Francisco peninsula".
Valve's last major acquisition was in 2008, when it snapped up Left 4 Dead developer Turtle Rock Studios.
We've contacted Valve for more information.