As a guilt-ridden Barry vows to defend the city alone, metahuman Atom Smasher threatens an attack.
Barry and the team have a difficult decision to make when a stranger from Earth-2 shows up with an urgent warning about an evil speedster.
Barry and the team ally with the kidnapped Captain Cold's sister, but Barry feels duped when he learns Snart is working on something with his father; Joe faces a difficult decision.
Barry and the team desperately search for another Firestorm match for Dr Stein; Barry and Patty grow closer.
The Flash receives a shock when Dr Light comes through the portal. She also brings some alarming news concerning Zoom.
Barry decides the time has come for him to face up to speed demon Zoom, but as he concocts a perilous plan, it appears not everyone has faith in him.
Grant Gustin
Barry Allen / The Flash
Candice Patton
Iris West
Danielle Panabaker
Caitlin Snow
Carlos Valdes
Cisco Ramon
Tom Cavanagh
Dr. Harrison Wells