'The Flash' Finds Its Pied Piper 

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confirms. He will appear in the 11th and 12th episodes.

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Hartley Rathaway, who later becomes Pied Piper and a member of the Rogues, is a genius who used to work at STAR Labs until he had a falling out with the mysterious Dr. Harrison Wells (Tom Cavanagh), the brains and money behind the particle accelerator. Following the explosion that created the metahumans, Hartley lost his hearing but started creating sonic weapons that he uses to destroy Harrison's latest creation: The Flash (Grant Gustin).

Mientus is the latest addition to a guest cast that includes Victor Garber as Dr. Martin Stein, original heroine Amanda Pays as Dr. Tina McGee, Dominic Purcell as Heatwave and Clancy Brown as General Wade Eiling.

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made a huge splash for The CW on Oct. 7, premiering to a massive 4.8 million viewers and a 1.9 rating among the advertiser-coveted 18-49 demographic — the second-biggest debut for the network behind

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