Nick investigates a series of deaths and disappearances; a stranger shows up to avenge a friend who died at the hands of a Grimm.

(Originally Aired: Friday Nov 18, 2011)

WWE superstars and divas entertain troops; featuring performances by Mary J. Blige and Nickelback. From Fort Bragg in Fayetteville, N.C.

Detectives Benson and Rollins investigate when a mental patient says he witnessed a rape, but the alleged victim denies the assault happened.

(Originally Aired: Wednesday Nov 16, 2011)

David Ushery and Shiba Russell.

Host Jimmy Fallon; Michael Bublé performs.

(Originally Aired: Saturday Dec 17, 2011)

The U.S. Marshals Service identifies its 15-most-wanted criminals; following up on the hunt for a killer in Lake Charles, La.

The five remaining contestants compete as a team; contestants face elimination.

(Originally Aired: Monday Sep 05, 2011)

An impact from outer space slowly hinders the planet’s rotation, threatening mass destruction.

(Originally Aired: Saturday Dec 17, 2011)

An industrial accident releases a cloud of self-replicating nanotech robots that devours everything in its way.

(Originally Aired: Saturday Jan 01, 2005)

A pair of crew members are trapped outside in an airlock.

(Originally Aired: Sunday Feb 18, 2007)

Connor disappears; Matt believes his mission is over and Philip has won.

(Originally Aired: Tuesday Jun 28, 2011)

Actor Robert Downey, Jr.; actor Jude Law; comic Eddie Izzard; singer Rebecca Ferguson; singer Alesha Dixon.

(Originally Aired: Saturday Dec 17, 2011)

Actor Judah Friedlander; comic Hannibal Burress; comic Mo Rocca; comic Andrea Rosen.

(Originally Aired: Saturday Nov 19, 2011)

Alan Cumming, Faith Salie, Scott Adsit and Dave Hill.

(Originally Aired: Saturday Nov 12, 2011)