The celebrity singers choose songs that best showcase their duet partners' talent.

The 14th season begins with 12 new houseguests and four returning players who are among the most successful to ever compete in the house, but the past quartet will play for their own separate prize and not the $500,000 grand prize.

Michael, Sam and Jesse head down to the Everglades to track a lead, but things go horribly wrong when Sam is kidnapped by an unexpected foe. In prison, Fiona finds herself in hot water with a pair of dangerous inmates. An ally offers to help, in exchange for a dangerous favor.

Beck intercepts a secret weapon that gives any program who wears it increased strength and agility, but it also makes the program more aggressive and reckless.

When a severely injured man under the spell of hypnosis can't remember his identity, the hypnotist who put him under is called into the hospital - where he uses his psychic ability to connect Charlie and Alex.

Troy hopes to make a statement by catching an enormous gator; R.J. and Jay attempt to set a tagging record; and dead fish cause trouble for Liz and Kristi.

A long-standing rivalry over who's a better therapist leads to war when Kate steals Patrick, one of Charlie's group patients.

When Andy and Swarek respond to a noise complaint, they find a stabbing victim and Oliver Shaw's teenage daughter, Izzy, at the scene. When Izzy goes missing, her involvement in the crime makes it difficult for Shaw to be both a good officer and her protective father.

Louis and Mike finally see eye to eye, but Louis' paranoia may damage his budding friendship with Mike as well as his standing at the firm. Also, Travis Tanner rolls back into town, gunning for Harvey. Guest Stars: Eric Close, David Costabile, John Finn.

Wilfred becomes embattled with an unlikely foe, forcing Ryan to intervene.

Tyler finally lands a photo shoot featuring his childhood idol, but when Gibbs starts to get buddy-buddy with Tyler's icon, things don't go according to plan. Meanwhile, Neal serves as Milo's guinea pig for an invention that goes terribly awry.

Louie goes to Miami.

Jenna tries to stay friends with Matty, but his nonstop flirting and clingy behavior make it difficult.

Determined to get over Lisa once and for all, Milo revives an intense competition that once almost destroyed the guys' friendship. But he is soon forced to make a big decision when Lisa comes back into his life. And Neal struggles to prove that he's on a par with the rest of the guys.

Anne Hathaway, Moody McCarthy, Loudon Wainwright III

Denis Leary, Olivia Munn, Kenny Chesney

Superstar chef Neil Perry joins Gary and George for an Italian-inspired MasterClass.