An Evening with Mr. Yang

S3, E16: The Yin Yang Killer, a serial killer who was active when Henry was a cop then went silent, is back and wants to toy with the department again, this time singling out Shawn as his primary playmate. Mr. Yang challenges the cops with the opportunity to save his victims by solving his riddles. Yang has just sent them another one, along with a stopwatch. They have an hour and ten minutes to solve the riddle and save his latest victim. Cybill Shepherd and Rachael Leigh Cook reprise their roles in the season finale ... and watch for a secret celebrity in the role of Mr. Yang!