Tipped off to Vandal Savage’s whereabouts, the team infiltrates a munitions deal with Professor Stein as their leader. Surrounded by some of the toughest criminals in the world, things quickly go from bad to worse when Savage realizes they don’t belong there. A massive fight ensues and a piece of the Atom’s suit falls off and into the wrong hands, which could potentially cause disastrous consequences in the future. Stein realizes the best way to retrieve the missing piece is to contact a brilliant man – his younger self. He, Sara and Jax head off in search of young Martin Stein, much to Rip’s consternation. Meanwhile, Snart and Rory plan to steal a key element in defeating Savage but still unsure of his new teammates, Ray demands to come along on the mission.
Holmes’ tentative reconciliation with his father suffers a setback when Holmes and Watson discover Morland has been keeping a secret that threatens all of their safety. Also, Holmes and Watson investigate two murders connected to a for-profit college and its illegal recruitment practices.
Charlie decides to go a day without using his special abilities; Alex organizes a trip to Dana's cabin; Zach takes control of a life and death situation involving Dawn's college roommate.
Bellamy and Kane risk life and limb to rescue Clarke. In an attempt to avoid worrying about her daughter, Abby focuses on whether to open Mount Weather as a medical facility. Murphy plots to betray his former Chancellor.
When an associate of Red's is killed with a rare medieval device, Red realizes a lethal vigilante group from the Middle Ages has been resurrected; Liz considers her next move after receiving shocking news.
The chefs participate in a plating challenge by preparing visually appealing dishes using only snack food. Then, they cook for diners at a black-tie, finger-food event called Beefsteak. Appearing: Colin Hanks; Max Silvestri; Matt Selman; Jacques La Merde; and Neal Fraser.