In "Supergirl," the name Hank Henshaw has long been a cover for J'onn J'onzz, the last Green Martian. While Hank has referred to the way he came to meet Kara and Alex's father Dr. Jeremiah Danvers and assume Hank's identity, fans haven't known much about it -- until now. "Manhunter" will explore the day J'onn met Jeremiah, played by "Lois and Clark" alum Dean Cain.

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J'onn J'onzz reveals the details of meeting Kara and Alex's father, DR. JEREMIAH DANVERS, and assuming HANK HENSHAW's identity, ON "SUPERGIRL," MONDAY, MARCH 21

"Manhunter" -- J'onn J'onzz reveals the details of meeting Kara and Alex's father, Dr. Jeremiah Danvers (Dean Cain), and assuming Hank Henshaw's identity. Also, Kara debates trusting someone new with her secret identity and Siobhan (Italia Ricci) plots against Kara, on SUPERGIRL, Monday, March 21 (8:00-9:00 PM, ET/PT) on the CBS Television Network.

"Supergirl" airs Mondays at 8 pm EST on CBS. Developed by producers Greg Berlanti, Ali Adler and Andrew Kreisberg, the series stars Melissa Benoist, Calista Flockhart, David Harewood and Chyler Leigh.