McNulty and his staff must act quickly to keep a terrorist ally from slipping away. Meanwhile, someone from JT's past figures into his misson of sending his old unit into harm's way when a high-risk mission requires the best of the special-ops teams.

In Columbia, JT is heading an undercover operation to nail the drug lord who attacked Angie. Now he has to finish a job they started together years ago.

Back in the Pentagon, Sam finds evidence on the CIA director and has him indicted.

When a general is kidnapped in Spain, JT and his team go to rescue him but find themselves in a turf war with local authorities.

JT and the team travel to Mexico to apprehend a drug lord who has allied himself with Al Qaeda and is smuggling terrorists into the US. Meanwhile Bobby receives some bad news.