A judge is killed, the killer sends the victim a part of a medal before he dies. When a former DA is killed, Barry finds a connection. Garfield was the arresting officer on the case, when his girlfriend/fiancée is shot, Garfield takes it personally. Flash must stop him before he crosses the line. Tina gets a job offer that would send her to California
An invisible man gets into Star Labs, and releases a neurotoxin with Tina inside the lab. Then he starts killing scientists who worked on the project. Flash must find the invisible man and save his friend.
A jazz musician friend of Julio's is about to be executed. An hour before the execution, a friend calls and says he has evidence that could exonerate their friend. Before Barry can contact him, he disappears. They have less than an hour to save a condemned man.
Barry is having trouble sleeping. Tina tries to use bio-feedback to help him, but it back fires on Tina. She joins a gang, and she's able to hold Flash at bay with her knowledge of his strengths and weaknesses. Barry has got to find a way to save his friend.
Barry considers moving, after Pike is acquitted of his brother's murder. Pike launches a nuclear missile to kill the Flash, who is sent 10 years into the future where Pike is now Mayor. The Flash's powers are now unstable and Tina refuses to help him because she blames him for leaving. He's got to find a way to get back to his own time.
A scientist and his business partner are trying to develop a being with super speed, their attempts fail. They manage to clone the Flash. Their creation learns quickly, but is emotional moral equivalent of a child. Barry must stop his twin.
A battery is stolen by a criminal calling himself the Mirror Master. He soon steals a crystal from Star Labs. Tina will get fired if they can't recover the crystal. Tina's mother comes for a visit, and an old friend of Barry's also stirs up trouble.