The first arc reaches its soul-searing climax as the T.H.U.N.D.E.R. Agents battle the might of the Subterranean Army for control of The Judgment Tower, but while they struggle, the Tower itself unleashes its unholy wrath. How can T.H.U.N.D.E.R. save humanity when they can't even save themselves?
"The Flash" Adds "Harry Potter" Star Tom Felton as Series Regular