"Lois and Clark" star Dean Cain will return to "Supergirl" in "Manhunter," which flashes back to the day Jeremiah Danvers (Cain) met J'onn J'onzz. One clip features a conversation between Danvers and Martian Manhunter, while another shows Hank Henshaw recruiting Alex to the D.E.O. Winn also deals with Siobhan's troubled job search and Cat struggles with the fact Kara has taken a sick day.

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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.