CSI investigator Barry Allen awakens from a coma, nine months after he was hit by lightning, and discovers he has superhuman speed.
S01E02 - Fastest Man Alive
Barry takes on a group of armed men at an awards ceremony, but side effects from his new super power catch up with him.
S01E03 - Things You Can't Outrun
Barry and Joe track a deadly metahuman with toxic gas powers, and Caitlin relives the night of the explosion that killed her fiancé.
S01E04 - Going Rogue
To steal a priceless diamond, Captain Cold acquires a specialized gun that can slay the Flash. Joe disapproves of Eddie and Iris dating.
S01E05 - Plastique
While trying to get Iris to stop blogging about the Flash, Barry investigates a general's connection to an explosive metahuman.
S01E06 - The Flash is Born
Barry takes on his childhood bully, who can now turn himself into steel. Iris finally coins the moniker "the Flash."
S01E07 - Power Outage
Using his metahuman power to siphon electricity, Blackout robs Barry of his speed, then sets his sights on S.T.A.R. labs and Dr. Wells.
S01E08 - Flash vs Arrow
The Arrow arrives to help the Flash investigate a series of homicides, but a metahuman who can control emotions turns them against each other.
S01E09 - The Man in the Yellow Suit
The Flash must confront the Reverse-Flash, the man who killed his mother. Caitlin gets surprising news about her fiancé, Ronnie.
S01E10 - Revenge of the Rogues
While the Flash prepares to vanquish the Reverse-Flash, Captain Cold and Heat Wave team up to kidnap Caitlin.
S01E11 - The Sound and the Fury
A former protégé of Dr. Wells uses sound waves to attack the Flash, while Iris faces trouble in her new job.
S01E12 - Crazy for You
Caitlin brings Barry out to a karaoke bar, hoping they both meet someone new; Cisco thinks about Hartley's dangerous proposition; Henry's snooping gets him into trouble.
S01E13 - The Nuclear Man
After Ronnie attacks a physicist, Barry and the team go after him. Joe enlists Cisco's help in the reinvestigation of Nora Allen's murder. Barry struggles with his relationship and his duties as The Flash.
S01E14 - Fallout
After the nuclear explosion separates Ronnie and Dr. Stein, Barry and the team believe both men are safe. Barry gets some important information about time travel.
S01E15 - Out of Time
Mark Mardon, having survived his apparent death during the dark 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.
S01E16 - Rogue Time
The Flash learns that Captain Cold and Heat Wave have returned to Central City. This time Snart has brought along his baby sister Lisa aka Golden Glider to help wreak havoc on the city.
S01E17 - Tricksters
A copy-cat-killer who goes by the name The Trickster starts setting off bombs in Central City. In order to stop the villain, Barry and Joe meet with the original Trickster, a criminal mastermind named James Jesse, who has been imprisoned for 20 years. Things quickly go from bad to worse when the Tricksters unite and take Henry prisoner. Meanwhile, Iris asks Eddie for help with a case, and flashbacks show how Harrison Wells came up with the idea for the particle accelerator.
S01E18 - All Star Team Up
Felicity Smoak and Ray come to Central City seeking help with Ray's suit; a meta-human releases deadly robotic bees; a group dinner does not go as planned.
S01E19 - Who is Harrison Wells?
Joe and Cisco visit Starling City and ask Captain Lance for help with their investigation into Dr. Wells; Laurel asks Cisco for a favor; Barry faces a new foe who can disguise himself as anyone he touches.
S01E20 - The Trap
Barry, Caitlin, Cisco, and Joe set a trap for Wells. Cisco uses himself as bait which puts him in great danger. Meanwhile, Eddie makes a decision regarding Iris, which leaves Joe a bit unsettled.
S01E21 - Grod Lives
Barry deals with the latest threat from the Reverse-Flash; Dr. Wells distracts the team by releasing Grodd on the city; Iris and Barry have a serious talk.
S01E22 - Rogue Air
Dr. Wells reactivates the particle accelerator and Barry has to move the Meta humans away. To do that, he needs help and he chooses to ask Captain Cold for it.
S01E23 - Fast Enough
When the particle accelerator is back online, Barry will have to go back in time to stop Eobard Thawne on the night of his mother's murder 15 years ago.