When Castle and Beckett learn that a murder victim may have been poisoned at an Old West-style resort, they visit the resort posing as newlyweds to uncover the truth.

The team's Thanksgiving plans are put on hold while they track an elusive international arms dealer in D.C. who recently murdered an MI6 officer who was Sloane's close friend.

When the CSIs investigate a murder in Miami's hippest fashion boutique, Horatio discovers that Julia's instability has turned her into a ticking bomb.

A lethal pipe-bomb blows a Manhattan townhouse and valuable evidence to pieces, forcing the CSIs to get creative in reconstructing the damaged clues that ultimately lead to the bomber. (TV-14)

The cyber crime team investigates when nine planes that departed from the same airport face a coordinated Wi-Fi attack while in flight.