Polygon reports. Fergusson joined Irrational in August to help finish up work on BioShock Infinite, a game that shipped to widespread critical acclaim on March 26. Now he's in the process of leaving Irrational.
"I am very proud of the work that I did and of the team and what they were able to accomplish on Infinite," Fergusson says. "Now with the game shipped successfully, I've done what I set out to do here and now I'm looking forward to the next chapter in my life and career."
When Fergusson joined Irrational, he followed a trail of major departures from the studio, including Art Director Nate Wells and Design Lead Jeff McGann. There's no word on what Fergusson's next move will be.