Tonight’s episode of Supergirl contained a major revelation about the true identity of David Harewood‘s Hank Henshaw character.
West Coast: Do not read this if you haven’t seen the Supergirl episode “Human For A Day” as SPOILERS are within!

How did that come to happening?
We spoke with Executive Producer Andrew Kreisberg on set last week about the decision… which came to them while they were on set for the pilot. “When you’re on the set of a pilot, you start seeing the sets, and you start seeing the actors, and you start thinking about what we could do next, and what kind of possibilities there could be… all of us were just so in love with David [Harewood], and so happy to have him on the show, and just loved everything he was doing with Hank,” Kreisberg recalls, though watching and admiring Harewood’s acting had Kreisberg, Geoff Johns, and Greg Berlanti all coming to the same conclusion at the same time.
Originally, Hank was going to have a different backstory… but the producers found that it all matched. “He’s had to sort of lead this crazy existence pretending to be Hank Henshaw. He doesn’t want Supergirl around; she could mess everything up. And then we realized it all fits,” Kreisberg says. But first, he and fellow Executive Producer Allison Adler took David Harewood out to lunch to tell him the news… and his biggest fear was actually humorous.
“He was like ‘I’m not going to be Shrek, am I?’ That was his biggest fear,” Andrew laughs.
“It is so spectacular. It’s just amazing, and then the more we thought about it, everything just sort of flowed from that… we’ve got White Martian episodes, and Jemm… it’s sort of the secret of Supergirl, that within the body of the series of Supergirl, there is a Martian Manhunter series rolling throughout it,” Kreisberg says, aware that many fans had speculated that Hank was the Martian Manhunter, but it would always be with a ‘I hope’ kind of glee.
Supergirl airs Mondays at 8PM on CBS. Come talk about tonight’s episode on our forum and don’t think we’re done talking about this development — over at KryptonSite.com, we have video interviews with actors David Harewood and Chyler Leigh where they talk about the news!