Victor Garber will play Dr. Martin Stein in the CW's The Flash TV series.
Stein is one-half of the character Firestorm, with the other half, Ronnie Raymond, being played by Robbie Amell.
THR says the role is major and recurring with Victor Garber slated to appear in the 12th episode.
The description for Dr. Martin Stein reads: Dr. Stein is a brilliant but arrogant nuclear physicist who has sacrificed everything, including a marriage, for his work in transmutation. After he discovers the particle accelerator fused him with the younger, more impulsive Ronnie Raymond, he races to find a way to separate the two before it's too late.
You can read some spoilery details and images about Firestorm that Amell previously posted.
Garber is known for Alias, Argo and Titanic.
The Flash airs Tuesdays at 8pm ET.