After Liz takes her ex-boyfriend, Dennis, back simply because he asks, Jack takes it upon himself to mentor her as he thinks that she is leading a life of mediocrity. Meanwhile, Tracy gets a tattoo in the face, Jenna gets botox and collagen injections, and Josh is given two black eyes by an angry Liz Taylor.

Jack bumps Jenna's scheduled appearance on 'Late Night with Conan O'Brien' by booking new star Tracy. Jenna, still irate over watching the show change to "TGS with Tracy Jordan," lashes out at Liz. To make matters worse, Tracy's gone off his medication and he's about to go on national television.

When Liz finally dumps her boyfriend Dennis, she prowls the singles scene under Jenna's tutelage. Love also stinks for Jack, as he discovers dating a Bush administration official has its downside. And Tracy and Toofer clash, which lands both in sensitivity training.

Dennis becomes a New York City celebrity after jumping in front of a train and saving someone who fell on the tracks. Meanwhile, Jack desperately tries to persuade Tracy to become the celebrity face of the Republican Party.

In the second season finale, Jack moves on to a new job involving politics in Washington, but the position is not quite what he anticipated. Meanwhile, Liz suffers a pregnancy scare, Kenneth confronts rival page Donny when applying for a summer job, and Tracy works on his latest invention.

While Jack puts together the perfect 50th birthday party for himself, home videos inspire him to try to recreate his happiest moment. Dennis decides to tell Liz about his addiction. Meanwhile, Kenneth and Pete work to make Tracy's childhood dream come true.

Liz schedules a root canal to avoid feeling lonely on Valentine's Day; Jack woos an attractive and successful TV host; Jenna's stalker loses interest.

Jack becomes even more entangled in his love triangle between Avery Jessup and Nancy Donovan, and he turns for advice to Liz, who is focusing on her own romantic problems. When Liz can't find a date to Floyd's wedding, she revisits her old boyfriends in hope that a spark will reignite. Meanwhile, Tracy continues his journey to earn his egot.

A reality TV series trails Tracy, which Liz tries to exploit for her own gain. Jack does his own exploiting: He attempts to make a fast buck off natural-disaster telethons. And Lutz sets out to increase his worth in the event of an apocalypse.

Chaos builds when bigwig Hank Hooper marks "TGS" for cancellation, yet Jack persuades him to let the staffers stage the show's 100th episode.

With their show targeted for cancellation, the "TGS" crew desperately scramble to mount a top-notch production for their 100th episode. Meanwhile, Jack reconsiders a vital decision in his life, and Jenna mulls over motherhood.

Criss and Liz decide to celebrate Valentine's Day, but they need to buy a dining room table first. Jack entertains his mother-in-law, Diana, as Jenna frantically looks to Pete to fill in last-minute as the producer of her first live performance on "America's Kidz Got Singing." Back at the office, Tracy and Frank try to help Lutz find someone to spend Valentine's with.

Criss and Liz decide to celebrate Valentine's Day, but they need to buy a dining room table first. Jack entertains his mother-in-law, Diana, as Jenna frantically looks to Pete to fill in last-minute as the producer of her first live performance on "America's Kidz Got Singing." Back at the office, Tracy and Frank try to help Lutz find someone to spend Valentine's with.

Jack feels unworthy of his latest award and attempts to redeem himself by taking on the writers in a strategic board game. Liz believes she's cursed on St. Patrick's Day when her ex-boyfriend Dennis shows up to derail her relationship with Criss. Meanwhile, Hazel struggles to keep the peace between Tracy and Jenna.

After an encounter with Dennis Duffy, Liz and Criss decide to take drastic measures to start a family. As Liz looks toward the future, Jack and Jenna evaluate their own self-worth, and Tracy laments a shocking medical diagnosis.