Photo Flash: Sneak Peek - Kelsey Grammer, James Marsden Guest Star on Tonight's 30 ROCK

In tonight's episode of NBC's 30 ROCK entitled 'Idiots Are People Three!', Broadway veteran Kelsey Grammer guest stars as himself along with Denise Richards, Will Arnett and James Marsden. In the episode,Tracy Jordan (Tracy Morgan) challenges Liz (Tina Fey) by leading his own protest in defense of idiots everywhere. Jack (Alec Baldwin) faces off with Devin Banks (Will Arnett) yet again, but still finds time to interfere with Liz's relationship by giving Criss (James Marsden) an ultimatum.

Five-time Emmy Award winner and 2010 Tony Award nominee Kelsey Grammer recently starred on Broadway in the Tony Award-winning revival of LA CAGE AUX FOLLES. He can currently be seen on TV in the Starz network's critically acclaimed series 'Boss' and starred in the long-running NBC comedy 'Frasier'.

Multiple award-winning comedy 30 ROCK is told through the comedic voice of Emmy and two-time Golden Globe winner Tina Fey as variety show producer Liz Lemon. The series also features two-time Emmy and three-time Golden Globe winner Alec Baldwin as top network executive Jack Donaghy and Emmy nominee Tracy Morgan as Tracy Jordan, the unpredictable star of Lemon's hit variety show, "TGS with Tracy Jordan." Lemon constantly has her hands full, juggling corporate interference from Donaghy and off-the-handle star antics from Jordan, all while attempting to salvage her own personal life.

Also rounding out the cast are three-time Emmy nominee Jane Krakowski as Jenna Maroney, the co-star of "TGS"; Scott Adsit as the variety show's producer Pete Hornberger; Emmy nominee Jack McBrayer as Kenneth, the over-eager and effortlessly endearing NBC page; Judah Friedlander as Frank, the sardonic slacker on the writing staff; and Keith Powell as Toofer, the sophisticated yet sarcastic, Harvard-alum writer.

View photos from tonight's episode below!

Photo credit: Ali Goldstein/NBC