Barry discovers his powers and puts them to the test, only when he finds its no longer a test but the real thing when he encounters a certain someone.

Barry changes into the Flash when six gunmen storm a university event honoring a scientist, but his heroics don't match up to his expectations. Meanwhile, Iris becomes even more intrigued by the "red streak."

Barry and the team go after the Mist, who possesses toxic gas powers, and they reflect on the night Caitlin's fiancé died. Meanwhile, Henry gets a long-awaited visit from Joe, and Iris and Eddie continue to keep their romance a secret from Joe.

The Flash battles Captain Cold after the villain is involved in a robbery and plots to steal the Kahndaq Dynasty Diamond.

After a bomb explodes downtown, the army rolls in and takes over. When Joe learns Iris is writing about 'The Streak' and tries unsuccessfully to have the story stopped, Barry decides to have The Flash pay her a visit.

The Flash faces a new meta-human named Tony, who can turn himself into girded steel at will.

The Flash goes up against Farooq aka Blackout, a metahuman who can harness electricity.

Barry is thrilled when Oliver, Felicity and Diggle come to Central City to investigate a case involving a deadly boomerang.

The crossover continues on Arrow S03E08 The Brave and the Bold.

Barry enjoys the annual tradition of tree trimming and gift exchange with Joe and Iris. He gives Iris a touching gift, but the moment is interrupted by Eddie’s arrival.

While Barry strives to become fast enough to defeat Reverse-Flash, Captain Cold returns to Central City with a partner and takes Caitlin hostage to force a confrontation with the Flash.

Dr. Wells' former protégé, Hartley Rathaway, returns to seek revenge on his mentor. Meanwhile, Iris is hired as a cub reporter; Cisco recalls his first day on the job at S.T.A.R. Labs; and Joe asks Eddie for a favor but asks him to keep it a secret from Barry.

Caitlin takes Barry out to a local karaoke bar to help them both find new loves. Caitlin strikes out but Barry meets a sports reporter and asks her out for a date. Meanwhile, Cisco considers Hartley's dangerous offer; and the team search for Shawna, a meta-human with teleportation powers who just busted her boyfriend out of Iron Heights.

While Barry, Harrison, and Caitlin hunt down Ronnie, who has attacked a man, Joe recruits Cisco to help him learn the truth about who murdered Nora Allen.

Martin and Ronnie are separated, only to realize that they must learn how to rejoin before Eiling hunts them down and kills them... and the Flash. Meanwhile, Joe shows Barry the 3D images from the Nora Allen crime scene, and Barry asks Martin for advice on time travel.

Mark Mardon, having survived his apparent death during the black-matter explosion, returns seeking revenge on Joe for the death of his brother Clyde... and has the same weather-manipulation powers as his deceased sibling.