To protect a key witness who is en route to testifying against a deadly drug cartel, Team Scorpion takes her on the run, with the cartel hot on their heels.

Team Scorpion must work with Toby’s nemesis, Quincy Berkstead, and his wife, Amy, Toby’s ex-fiancée, when they are locked inside an artificially intelligent doomsday bunker that aims to kill them. Also, Walter is distracted by his recent dream where he is married to Florence, not Paige.