Sylvester goes under cover in a federal prison in hope of saving three judges' lives; the team must orchestrate a prison break when Sylvester's life is threatened.
An explosion sends a top-secret submarine to the bottom of the ocean with limited oxygen, a self-destruct function that's about to activate, and Walter, Cabe and Happy on board.
Team Scorpion must stop a sabotaged runaway subway train with Paige and Ralph on board. Also, in his attempt to impress Happy, Toby has his first boxing match.
