Special Guest Stars Rick Cosnett as Eddie Thawne Wentworth Miller as Leonard "Len" Snart Robbie Amell as Ronald "Ronnie" Raymond / Firestorm Victor Garber as Dr. Martin Stein / Firestorm Dominic Purcell as Mick Rory Guest Stars Patrick Sabongui as David Singh Teddy Sears as Jay Garrick John Wesley Shipp as Dr. Henry Allen Vito D'Ambrosio as Mayor Anthony Bellows Isabella Hofmann as Clarissa Stein Adam Copeland as Al Rothstein / Atom Smasher Co Starring Logan Williams as Young Barry Allen Aaron Craven as Attorney Greg Turk Boyan Vukelic as Kendell