At first it seems as if “The Headlands,” the beguiling new play by Christopher Chen that opened on Monday at the Claire Tow Theater, is going to fall into the trap that many staged detective stories do. Instead of enacting live conflicts, they narrate crimes that occurred in the past. If I wanted that kind of experience, I’d plug in my earbuds and listen to “Serial.”

But “The Headlands,” a mystery set in the Bay Area with a vigorous nod to “Vertigo,” is merely feinting in that direction. Chen’s main character is a 30-something Google engineer named Henry (Aaron Yoo), whose sideline of solving cold cases is initially presented as just another aspect of his nerd personality.

“Tonight I’m going to tell you about one particular case I studied,” he begins, as if he were hosting a podcast.

That case is the murder, 20 years before the action, of George Wong, the co-owner of a kitchen contracting business in the Sunset District. No one was ever charged, no motive adduced, and Wong’s wife, Leena, who discovered the body and might have known more, is now dead of cancer. Still, Henry comes to suspect from piecemeal clues that the killing was more than the random burglary gone bad that police had declared it to be.