From USA Network's official press release:

After eluding capture and disappearing years ago, the famed Yin Yang serial killer is back with sights set on Shawn.

Psych stars James Roday as Shawn Spencer, Dule Hill as Burton "Gus" Guster, Corbin Bernsen as Henry Spencer, Kirsten Nelson as Karen Vick, Maggie Lawson as Juliet O'Hara and Timothy Omundson as Carlton Lassiter.


Source: USA Network
(Image courtesy of USA Network)