Barry teams up with Wells to figure out a way to close the breaches, but they are distracted by a meta-human nicknamed Tar Pit who can transform into liquid asphalt. Iris is concerned for Wally’s safety after she finds out about his drag racing hobby. When he refuses to stop she makes a bold move that puts her in danger.
Alicia argues against Judge Schakowsky when she learns that a former bond court client was wrongfully imprisoned. Also, Diane assists the student editor of a college newspaper when the school threatens to fire her for writing a politically charged article.
Katie’s first mission forces her to question her commitment to the cause; Will’s search for Geronimo doesn’t sit well with the resistance; and Bram’s girlfriend shares a secret with him.
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.
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.
Mike’s worst fears have come true. He’s been arrested for fraud and is under investigation by a ruthless government prosecutor, Assistant US Attorney Anita Gibbs. Meanwhile, Jessica and Harvey must figure out how to build a defense for Mike, knowing full well that he’s guilty of the crime for which he stands accused. And Rachel must come to terms with her family’s reaction to the news that her fiancé is not the person he claimed to be – and that he could soon be in prison.
Diggle must learn to trust his brother Andy when an enemy of their wartime past, an agent of the criminal organization Shadowspire, pays a visit to Star City. However, Diggle learns more than he bargained for about their shared time at war. Meanwhile, Oliver has to learn a whole new way of life.
Peggy’s search for the truth about Zero Matter puts her on a collision course with her superiors as Howard Stark barnstorms in.
With Simon being held captive at The Hotel DuMort, Clary pleads with Jace, Alec and Isabelle to help her rescue her best friend. As the team readies for the mission, Jace helps Clary learn more about her Shadowhunter powers, Isabelle turns to her favorite Seelie for Intel, and Alec begins to question Jace’s motives and his place in their partnership. Meanwhile, a very scared Simon gets very up close and personal with Camille, the leader of the vampire clan.
When Cisco gets a vibe of Eobard Thawne, Barry and the team don’t believe it. But, after an attack at Mercury Labs, Christina McGee confirms that the Reverse Flash is back. Meanwhile, Iris and Francine share a nice moment that brings Iris closer to her brother, Wally.
