Derek's confidence is shaken like never before as he faces off with Addison over what course is best for their dying pregnant patient; Cristina calls the abilities of a renown surgeon into question after she botches a standard procedure; and Bailey, who has decided to pursue a fellowship in Pediatrics, is appalled by the Chief's less-than-stellar recommendation letter.

Danny Glover guest stars as Darnell's father who comes looking for him in Camden only to raise Earl and Randy's suspicions. However, a family reunion leads to father and son partaking in one last undercover mission.

The contestants compete in the rain during a very physical immunity challenge.

Fashion Week hits town which causes problems for the staff at Mode. Betty has to split her time between working on her Yeti assignment and working with a new designer. Elsewhere, Wilhelmina has lost her way because of Connor and there's a new person working at Mode.

Kath finds out that technically she is still married, something she wants to change immediately. Suddenly everyone ends up at a roller derby.

The team investigates a sci-fi convention when a woman in a medieval princess dress is found murdered. With Booth's back injured, Agent Payton Perotta steps in once again to help.

While Langston testifies in the trial of a respected Congressman, new evidence sends the CSIs back to the lab to reopen the investigation.

Chef Ramsey has the remaining 14 chefs make a visit to the meat locker to learn about every cut of beef, then gives them a challenge by declaring the kitchen a steak house for the night.

Archer and Naomi grow romantically closer, while Addison suspects her brother is up to her old tricks again.

Valentine's Day in the ER finds Neela spellbound by Brenner. Determined to have a baby, Banfield comes up with a plan but has difficulty getting her husband on board. Neela performs surgery on a young girl's mother. Dr. Carter surprises the staff with a visit to the ER. Gates treats a strange patient who may have ingested a toxin while hunting for mushrooms.

Facing pressure from Sam and Fiona, Michael agrees to help bring a Haitian murderer to justice.

A helicopter pilot is rendered blind during a live televised traffic report. The blindness causes him to crash the helicopter.

When suspicions arise that an FBI agent might have gone rogue, Ellis investigates the individual's ex-girlfriend and Barker gets close to him by going undercover at a security company.

The experts use new technology to figure out what happened to four u-boats on their last voyage.

The theme for this episode is future. All things futuristic are discussed, including space travel and aliens.

Lee and Tim decide to try and throw Lucy a 30th birthday party but they both have different ideas. Lee is not happy when Lucy shows up at the party with a man and decides to try and get rid of him.

Just before Valentine's day, Helen posts Alex's personal details on a dating website, leading to an old girlfriend connecting with Alex again.