With the previous episode, 30 Rock's tradition of having freaking great guest stars (Dean Winters, in the specific case of Episode 6) was inaugurated, and the trend is maintained admirably in the seventh show of the season, for which Tina Fey received an Emmy nomination as a writer. It features a happily self-deprecating appearance by one of America's top talk show hosts (and, coincidentally, a star of NBC, which produces 30 Rock): Conan O' Brien.
Conan's presence (as himself, obviously) is explained by Jack's latest attempt at keeping Tracy on the radar: instead of Jenna, it's the capricious actor that will appear on Late Night with Conan O' Brien that evening. Unfortunately, Tracy has been on the show before, and on that occasion he tried to stab Conan. Plus, he behaves even more strangely than usual, due to the new medication prescribed by Dr. Spaceman (Chris Parnell). In addition, Liz has to deal with Dennis' presence in her apartment, a fact that gets weirder by the minute.
Aside from Fey's writing, the success of the episode rests on three performers: Tracy Morgan, always fun to watch (just listen to his anecdotes about his son or meeting Sharon Stone); Parnell, who makes his debut on the show as the incredibly unreliable doctor (by the way, about his name: Tracy pronounces it as one could expect, everyone else calls him "Spuh- Che-man"); and Conan, who takes the "bonkers" element of his personality he uses on his show and amplifies it to the max. The result is essentially a comedic duel between him and Tracy. Who wins? Too close to call, but once again it's 20 minutes of great television.