Yet another Valve virtual reality engineer has left the Half-Life company to join Oculus VR, the firm behind the Oculus Rift headset that was recently purchased by Facebook for $2 billion.

Aaron Nicholls, who spent four years working on VR at Valve, is now working at Oculus VR as a “Scientist.” He’ll be working out of Oculus VR’s Bellevue, Washington R&D lab, Oculus VR said in a statement.

“Moves like this are always a little scary, but I’m very excited and can’t wait to start in the morning,” Nicholls said last night.

Nicholls is the third Valve employee to join Oculus VR in as many weeks. Veteran Valve VR engineers Atman Binstock and Michael Abrash joined the company earlier this month. Nicholls previously worked at Microsoft for 14 years and helped ship games in the Halo and Gears of War franchises.

For more on Facebook’s acquisition of Oculus and what it means for the future of VR, check out GameSpot’s roundup of everything you need to know.