While Harry goes back to Earth-2 with Barry and Cisco to rescue his daughter Jesse from Zoom, Joe, Caitlin, and Jay deal with a new metahuman menace.
Six months after the events of the Singularity, Central City holds a rally in Flash's honor. However, Barry doesn't want to attend since he knows who the true hero is who sacrificed his life to save the city. Meanwhile, a new giant-sized metahuman launches an attack on Flash.moreless
Martin and Ronnie return to S.T.A.R. Labs to help the team as Barry must make a life-changing decision thanks to Harrison's machinations.
Barry turns to Captain Cold for help when Harrison's plans threatens the imprisoned metahumans. Meanwhile, Iris makes a decision concerning herself and Eddie after the team rescues the officer from Harrison's underground base.moreless
After the nuclear explosion outside of Central City, Eiling comes after Firestorm, intent on using him to develop super-soldiers. Meanwhile, Mason asks Iris to help him investigate S.T.A.R. Labs, and Martin and Barry discuss the possibility of time travel after Joe shows Barry what he found at the old house.moreless
When the merged Martin and Ronnie attack a physicist, the team sets out to bring in "Firestorm". Meanwhile Joe recruits Cisco to help him investigate the house where Nora was murdered.
Barry finds the man who killed his mother, but soon discovers that his opponent is faster than he can imagine. He turns to Joe and Harrison for help trapping his opponent, but things don't go as planned. Meanwhile, Caitlin discovers that Ronnie is alive and enlists Cisco's help to find him, and Eddie asks Iris to move in with him.moreless
Oliver, Felicity, and Diggle come to Central City to track down a boomerang used in a murder, and team up with Barry. However, when Barry falls under the influence of a villain who puts him into a fit of rage, Oliver must battle his friend before he kills someone. Meanwhile, Eddie tries to form an anti-Flash task force when he believes that the speedster poses a danger to the city.moreless
A metahuman killer goes after his enemies using his ability transform into poison gas. Meanwhile, Caitlin revisits the site where her fiancé Ronnie died, and Joe visits Henry in prison.
Stephen finds his father at ULTRA after some of The Tomorrow People abduct him. And Stephen wants his revenge on The Founder for taking his family apart.
Stephen is still walking a fine line with his ULTRA partner Hillary who continues to question his loyalties.
When ULTRA and The Tomorrow People both learn of a breakout using her powers to benefit humans both sides seek her out to join their cause.
Meanwhile Morgan takes a risk and betrays Jedikiah's trust to help The Tomorrow People but Jedikiah learns something from her that is an even bigger surprise.
Julian returns with a vengeance but when he's caught by ULTRA he is forced to strike a deal that could cost him and Stephen their lives.
John disobeys Cara's orders again when he learns Julian has discovered the location of The Tomorrow People's lair.
Meanwhile still plagued by nightmares from her near death experience Astrid turns to John for comfort and support.
After receiving some shocking news Stephen attempts to restore order in both his worlds by striking a deal with Jedikiah.
Cara and Russell contend with a new break-out and must also deal with an ULTRA trap.
Meanwhile Jedikiah is closer to developing a secret technology that could change his future.
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.
Stephen feels uneasy about fellow ULTRA trainee, Hillary, who has her own secret agenda. After his mother insists the family go camping with Peter, Stephen asks John and Cara to ensure everything is okay with Astrid while he's gone.
Stephen and his fellow ULTRA trainees are given a test by Jedikiah to determine their worthiness as Agents but not everyone is happy to work as a team.
Cara is faced with a visitor from her past and John works with a new breakout while Russell is sent on a dangerous recon mission that could force a clash between different groups of Tomorrow People
When John finds himself in a dangerous situation Stephen finds he is unable to help without revealing his duplicity to ULTRA. Also not satisfied with the answer he discovered about his father's death Stephen decides to take drastic action to find the truth with help from his fellow Tomorrow People.
Cara and Russell negotiate a trade with Jedikiah which ultimately makes Jedikiah take a big risk.
Stephen is determined to uncover what he hopes is the key to finding his father, and crafts a plan with The Tomorrow People that involves getting inside Jedikiah’s head. Meanwhile, Cara and Russell encounter an uninvited visitor in the subway tunnel base.
Stephen takes a risky opportunity and snoops around ULTRA.
After Stephen decides to have some fun with his newfound powers, Jedikiah takes extreme measures to ensure it doesn't happen again.
John feels tension between himself and Cara after he and Russell return from their trip while Stephen decides to try and handle a dangerous new breakout on his own but finds himself in over his head and needing help from his fellow Tomorrow People.
Stephen becomes even more determined to find out what happened to his father after having a moment of clarity about him.
Stephen and Russell head out for a night of fun only to run into a potential new breakout. They report back to John and Cara about the discovery but want to keep a low profile from ULTRA.
Russell learns of his father's death and struggles with the decision of whether or not to return home. John volunteers to go with him to keep him out of trouble.
Meanwhile Jedikiah has a secret that could destroy his career.
After Stephen breaks ULTRA protocol during a training exercise, Jedikiah's mysterious boss insists on meeting him. After learning Jedikiah is unable to help him Stephen turns to John who is only interested for selfish reasons.
Elsewhere Cara and John disagree on a dangerous plan when some of The Tomorrow People become desperate to attend a party in the outside world. And when Stephen again bails on plans with Astrid she decides to find out what he is really up to.
When ULTRA's most wanted man Killian McCrane resurfaces after years in hiding Stephen enlists John's help in tracking him down. John agrees but changes his mind when he learn Killian isn't after Jedikiah as everyone first believed.
Stephen still wants to help but Cara explains the history between Killian and John: A history that brings back memories from John's past and forces him to do something he never thought he would ever do again.
Meanwhile Stephen's mom becomes suspicious of his whereabouts and activities placing him in an awkward position.
When Stephen is convinced by Astrid to attend a party he is shocked to discover one of his classmates is in trouble, he reaches out to John and Cara for help but they refuse to come to his aide because they don't help humans. Stephen must deal with feelings from his own traumatic past when he tries to secretly get Cara to help anyway.
With Stephen now working at ULTRA, John gives him a mission to infiltrate their computer to give The Tomorrow People an advantage in finding new break-outs.
Stephen looks to his fellow Tomorrow People for help when ultra attempts to scan his brain. John refuses to help forcing Cara to help Stephen secretly.
ULTRA and Stephen both search for a new break out who is using his powers to commit crimes. when an ULTRA SWAT team arrives stephen again calls on John, Cara and Russell for help.
John attempts to convince Stephen to spy on ULTRA while continuing the search for his missing father.
When Stephen Jameson begins hearing voices and waking up in strange places he discovers he is a member of a highly evolved race of people with superhuman abilities. Seeking answers leads him to discover others of his kind called The Tomorrow People. He discovers The Tomorrow People are caught in a struggle for survival against an evil paramilitary group known as ULTRA who seek to destroy them all.
Stephen also learns there may be more to the mysterious disappearance of his father than he'd ever imagined and he discovers his own ties to Dr. Jedikiah Price, ULTRA's ruthless leader could be deadly.
Zach has a disagreement with Nick and takes part in auditions for a student film.