Russell Edge

Beckett and Castle must stop a series of events that could result in a war.

Castle and Beckett discover that the killer they are pursuing is part of an international conspiracy, and they must work with a CIA agent with whom Castle has a history.

Addison, Amelia and Fife try to save Maya and her unborn child; Sam makes a grim discovery; Cooper makes a valiant effort with Charlotte; an unexpected death leaves everyone stunned.

Peggy must put a dangerous plan into action to stop Whitney Frost and save Dr. Wilkes; Thompson makes an unexpected move.

Sousa and Peggy try to make a deal with Whitney Frost; Howard Stark helps the SSR in hopes of eliminating Zero Matter.

The team uncovers a methedrine lab in a murder victim's apartment; an unscrupulous FBI agent has a secret life.