Working as a C.S.I. in the Central City Police department, Barry Allen’s (Grant Gustin) life was forever changed the night the S.T.A.R. Labs Particle Accelerator exploded, creating a dark matter lightning storm that struck Barry, bestowing him with super-speed and making him the fastest man alive. But Barry wasn’t the only person who was given extraordinary abilities that night. The dark matter also created meta-humans, many of whom have wreaked havoc with their powers on the city. Barry teamed up with his friends at S.T.A.R Labs, Caitlin Snow (Danielle Panabaker), Cisco Ramon (Carlos Valdes), and Dr. Harrison Wells (Tom Cavanagh), to protect the people of Central City as The Flash from these powerful new threats.
After losing both his parents to speedster villains Reverse Flash and Zoom, Barry races back in time saving his mother ultimately resetting the timeline and erasing his life as The Flash. In this new timeline, Barry had a happy life with his parents, however, it was short-lived once he realized that his memories of the old timeline were disappearing – soon he wouldn’t even remember he was The Flash. Barry runs to the future, resetting the timeline back, only to discover things are not what they once were and, in resetting the timeline, a new threat emerged in Central City – the first speedster in history, Savitar. But Savitar is destined to kill Barry’s fiancée Iris West (Candace Patton) in the future. Working together with his adoptive family, Joe West (Jesse L. Martin) and Wally West (Keiynan Lonsdale) and the rest of Team Flash, they defeat the evil speedster and ultimately save Iris’ life. But it comes with a cost, when they discover the Speed Force has become unstable and threatens to destroy Central City… and the only way to save it is for Barry to make another sacrifice and go into the Speed Force – leaving Iris and his loved ones behind.
In Barry’s absence, Team Flash does their best to keep moving forward without the Scarlet Speedster and defeat all the threats that come their way. However, when a new villain too powerful for them arrives in Central City, the team realizes that there is only one person that can help – The Flash. Now, the team must devise a plan to free their friend from the Speed Force before the city is destroyed… knowing that the Flash that comes out of the Speed Force may not be the same hero as the one who went in it.