Special Guest Stars David Ramsey as John Diggle Guest Stars Violett Beane as Jesse Wells Teddy Sears as Jay Garrick Audrey Marie Anderson as Lyla Michaels / Harbinger Co Starring David Hayter voices King Shark Sylvesta Stuart as Technician Haley Beauchamp as Dr. Tanya Landem Benjamin Arcé as Guard #1 Spencer Graham as A.R.G.U.S. Agent #2