Clark meets Zatanna (guest star Serinda Swan) at a comic book convention, where she tells him her father charmed a copy of the comic book “Warrior Angel” and it holds magical powers. A young man named Stephen (guest star Carlo Marks) steals the comic book and develops super powers, transforming himself into Warrior Angel and saving Chloe from a horrible accident. Meanwhile, Lois becomes jealous of Clark’s relationship with Zatanna.

In the climactic season finale, everyone bands together in an effort to stop Samuel (Robert Knepper) from taking the lives of thousands. Peter (Milo Ventimiglia) joins forces with his most unexpected ally to save Emma (guest star Deanne Bray). Meanwhile, H.R.G.’s (Jack Coleman) life hangs in the balance as he and Claire (Hayden Panettiere) find themselves trapped underground with oxygen quickly running out. Elsewhere, Hiro (Masi Oka) starts to come to grips with the decisions he has made and is called into action to help stop a disaster. Greg Grunberg, Ali Larter, Zachary Quinto and James Kyson Lee also star. David H. Lawrence XVII, Harry Perry, Todd Stashwick also guest star.

Castiel (Misha Collins) helps Sam (Jared Padalecki) and Dean (Ackles) hunt down Cupid (guest star Lex Medlin) on Valentine’s Day after townspeople start to kill each other for love. However, after Cupid tells them he’s innocent, they discover Famine (guest star James Otis), one of the Four Horsemen of the Apocalypse, has arrived in town.

When Lux (Britt Robertson) gets suspended from school, Cate (Shiri Appleby) does her best to convince Principal Dugan (guest star Merrilyn Gann, “Everwood”) to give Lux a second chance, but, unfortunately, her efforts may have made the situation considerably worse for Lux. Meanwhile, Baze (Kristoffer Polaha) is insulted when he finds out that Cate and Ryan (Kerr Smith) are hosting a radio station event at the bar across the street. Austin Basis also stars. Jeff Melman directed the episode written by Emily Whitesell.

Brooke (Sophia Bush) and Julian (Austin Nichols) try to find a balance between their personal lives and work as the movie shoot begins. Nathan (James Lafferty) and Haley (Bethany Joy Galeotti) receive a surprise visit, and Clay (Robert Buckley) supports Quinn (Shantel VanSanten) as she faces some unexpected news. Alex (Jana Kramer) sets her sights on Alexander (guest star Mitch Ryan), and Millicent (Lisa Goldstein) finds herself struggling with temptation.

American Idol's newest judge, Ellen DeGeneres, joins Simon Cowell, Kara DioGuardi and Randy Jackson in Hollywood to begin winnowing down the contestants. The golden ticket contenders chosen from around the nation will endure a grueling rehearsal schedule and pressure-packed auditions as they vie for a coveted spot among the Top 24. Find out who will survive and who will go home during round 1.

When Jackie discovers Belle's sex toys, Belle takes her to a fetish club to prove that lots of people are open about sex. Belle hopes that liberating Jackie's libido will drive her back to her husband, who had an affair when they stopped having sex. Living with Jackie becomes impossible and a fight culminates with Jackie punching Belle. Later that day, Belle's client rejects her when he sees her bruise; it ruins the fantasy of 'Belle' for him. Belle heads home, feeling low, only to walk in on a very odd surprise. Meanwhile, Bambi is on her first appointment with a young aristocratic client, Byron, who she's in danger of falling for. When Belle is faced with writer's block, she calls Duncan who eases her worries.

Cuddy rises early to find Lucas is not in her bed. She quickly goes about her morning of tending to a sick Rachel as she tries to get ready. The nanny Marina arrives to deal with the baby, and Cuddy is about to leave for work when Lucas arrives after an all-night stakeout. Although she's late, she agrees to a morning quickie. As they start to get intimate, her blackberry rings with an emergency page from House. Cuddy ignores it and they continue. A minute later, she rolls over, frustrated. Lucas asks for another go, but she gets up to leave.

After three weeks in Los Angeles, Shirley, Gary and Brendan each have an opportunity that could transform their lives. Shirley has scored an audition to host a new psychic TV show called Spirited and is determined to get the job by any means necessary. Brendan is making an eco-documentary about the release of a California Condor back into the wild. The only problem is that he has neither the rare bird nor anyone to release it. Gary is on a quest to find an agent. He meets with a husband-wife producing team who offer to make him a show-reel, but tensions flare when Gary becomes visibly aroused during a romantic scene with the wife.