Katie A. Keane

Thanksgiving with Marshall's family is especially stressful for Lily because she thinks she may be pregnant. Elsewhere, Robin, Barney and Ted spend the holiday volunteering at a homeless shelter.

A professor from Lewis' past tips off the BAU to an alarming number of overdose deaths of patients who just completed rehab.

Determined to speak with Sara, Michael enlists T-Bag's help to get to the only phone in Sona: Lechero's; Lincoln attempts a daring rescue; Whistler comes clean to Michael, just as Mahone is tempted to fall back on a dirty habit; and Bellick makes an enemy while attempting to get back on his feet.

The clock is ticking, as the team goes in search of Gravitonium in order to help save the world.

After receiving a ransom call from the kidnapper of a Marine's daughter, the NCIS team learns that the girl's parents were recently separated after a marital indiscretion by the wife. Armed with that new information, Gibbs and the team focus their investigation on the woman's ex-boyfriend. Meanwhile, Abby's Halloween costume renders McGee and Tony speechless.