‘Do No Harm’: Meet the killer inside

There’s a new high-concept split-personality thriller on the block: NBC’s “Do No Harm,” starring Steven Pasquale as the successful neurosurgeon Jason and the destructive psychopath Ian, who takes over Jason’s body between 8:25 p.m. and 8:25 a.m. Of course, it’s not the first show in recent memory to try out the double life concept, including NBC’s “My Own Worst Enemy” in 2008 and “Awake” last year, neither of which made it out to a second season.

But the folks behind “Do No Harm” are heading into tonight’s premiere (10 p.m., NBC)?with confidence. “I think that ultimately you can only write the show you want to watch, and this was a show that I wanted to see on TV,” says executive producer David Schulner. “But definitely I took lessons from those shows, and I said this is going to be a show you’re going to want to watch every single week. The stuff that Ian does to Jason and Jason will do to Ian, it’s a wild roller-coaster ride, and it’s just thrilling and fun. That’s the big difference between those shows.”

That thrilling fun comes mostly from the ways in which Ian goes wild with Jason’s life while his more mild-mannered counterpart sleeps. “Ian’s a little bit like a cat. The cat wants to play with that mouse. He doesn’t want to kill it, because what fun would that be?” Schulner says. “So Ian’s going to do a lot of stuff to Jason. And then what’s great about Jason is he’s just as smart as Ian is and is sometimes two steps ahead, so there are traps in place.”

It’s more than just a game, however, when Ian takes over. “There’s a true danger to him,” Schulner says. “He’s truly menacing, and that’s why Jason needs to get rid of him.”

For Pasquale, that makes for a fascinating acting challenge. But at least he knows both characters’ fates are safe. “Ian’s aware that if he were ever to murder somebody, they would [both] go to jail,” Pasquale says, while stressing: “It really is a very real threat of something going very dark. Whether or not it happens will remain to be seen, but certainly that’s where all of the tension lies.”