Mercy (8pm, NBC) - James Van Der Beek joins the cast tonight as the arrogant new head of ICU who immediately clashes with Veronica.
Modern Family (9pm, ABC) - Minnie Driver guest stars as Claire's old friend, and Jay's racquetball game with Cameron (right) is marred by an awkward moment in the locker room.
American Idol (9pm, Fox) - Billed as a "Road to Hollywood" installment, this episode boasts guest judges Kristen Chenoweth, Joe Jonas, Neil Patrick Harris, Victoria Beckham, Mary J. Blige, Katy Perry, and Avril Lavigne. Must be a clip show of moments from the preliminary auditions.
Launch My Line (9pm, Bravo) - If you've been watching, tonight is the finale. The third season of "Shear Genius" premieres right after.
Psych (10pm, USA) - Shawn is suspicious when a man dies during a river-rafting outing with Gus's adreneline-junkie girlfriend.
Leverage (10pm, TNT) - Speaking of fake psychics, Luke Perry plays one tonight on "Leverage."