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.

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.

Peggy’s search for the truth about Zero Matter puts her on a collision course with her superiors as Howard Stark barnstorms in.

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.

Will faces unforeseen challenges on his first day at his new job. Katie receives her first assignment. Maddie reconnects with an old acquaintance. Carlos pays the price for Will’s collaboration.

Three months have passed since the tragedy at Mount Weather and our heroes learn that a bounty has been put on Clarke’s head. Unbeknownst to Clarke, a team led by Bellamy and Kane journeys deep into Grounder territory to save her. Meanwhile, Murphy finds his way to the mansion and discovers a very different Jaha on a very different mission.

As the clock counts down to the end of the world, Tommy finds himself up against his biggest challenge yet as Erica takes drastic measures to see her plan succeed. Malina tries to fulfill her great-grandmother’s prophecy to save the world with the help of Luke and Quentin. Emily and Ren desperately search for Miko. Carlos is faced with a life and death choice.