Plot: Barry Allen is a Central City police forensic scientist with a reasonably happy life| despite the childhood trauma of a mysterious red and yellow lightning killing his mother and framing his father. All that changes when a massive particle accelerator accident leads to Barry being struck by lightning in his lab. Coming out of coma nine months later| Barry and his new friends at S.T.A.R labs find that he now has the ability to move at superhuman speed. Furthermore| Barry learns that he is but one of many affected by that event| most of whom are using their powers for evil. Determined to make a difference| Barry dedicates his life to fighting such threats| as The Flash. While he gains allies he never expected| there are also secret forces determined to aid and manipulate him for their own agenda.
After a particle accelerator causes a freak storm, CSI Investigator Barry Allen is struck by lightning and falls into a coma. Months later he awakens with the power of super speed, granting him the ability to move through Central City like an unseen guardian angel. Though initially excited by his newfound powers, Barry is shocked to discover he is not the only "meta-human" who was created in the wake of the accelerator explosion – and not everyone is using their new powers for good. Barry partners with S.T.A.R. Labs and dedicates his life to protect the innocent. For now, only a few close friends and associates know that Barry is literally the fastest man alive, but it won't be long before the world learns what Barry Allen has become... The Flash.
Barry and Iris greet their future children, XS and Bart, only for a shocking secret to threaten their new familial harmony. Meanwhile, the Godspeed war intensifies and threatens to destroy Central City.
John Diggle arrives in Central City with a weapon to help Barry stop the Godspeed War. Meanwhile, Allegra and Ultraviolet's new bond is put to the ultimate test, while Joe and Kristen Kramer are hunted by a former colleague of hers.
When an army of Godspeeds attack Central City, Barry and Iris must put their family plans on hold and focus on the latest threat to their home. Meanwhile, Chillblaine is released from prison and claims to be reformed but Frost has her doubts.
When Ultraviolet returns to Central City, Allegra is determined to find her cousin and change her heart. Meanwhile, Joe finds evidence that Kristen Kramer may not be the good cop she appears to be.
Cecile is forced to confront her past in order to break free from a psychic prison. Meanwhile, Chester takes over for Cisco but makes a mistake that puts Barry in serious danger. Joe investigates Kristen Kramer's old military ties and discovers an unsettling truth.
