Career criminal Leonard "Len" Snart acquires a cold gun stolen from S.T.A.R. Labs and goes after a rare diamond... intent on stopping Flash cold after an earlier defeat. Meanwhile, Felicity comes to town to check on Barry, and Joe continues to give Iris and Eddie the cold shoulder after he learns that they're dating.moreless
Clarke and Finn grow closer as they try to communicate with the Ark. Meanwhile, Bellamy maintains order within the group.
While the Jabberwocky tries to free herself from Jafar's control, Jafar sends the Knave to steal from Alice... putting their friendship to the test. In the past, Cora sends the Knave to find Alice and offers him his heart if he succeeds.moreless
Stephen is upset with Jedikiah for going back on his word, forcing him to face The Founder.
In order to protect Astrid, Stephen must make a deal to bring in a powerful break-out and elsewhere John clashes with Cara which forces her to issue a harsh punishment.
A new crime lord, the Mayor, arrives in Starling City and starts bring in illegal guns. When Oliver tries to counter with a Cash for Guns event, Black Canary's friend sin is hurt and the female heroine sets out for revenge. Meanwhile, Diggle links up with an old friend and DA Donner asks Laurel out on a date.moreless
Kiera and Carlos are made aware of a bulk purchase of potential explosives which turns into a dangerous standoff.
Walter is forced to relive his past while investigating a series of spontaneous human combustions, while David Robert Jones begins his end game.
Kate's latest mediation case deals with an aeronautics company and a severance package for a terminated employee.