4 out of 5 stars

“The Unknown” couldn’t be a more apt title because, ultimately, after the full 75- minutes of David Cale’s thriller, you won’t know the answer to the play’s central mystery. And yet, it hardly matters because its solo performer, Sean Hayes, fresh from last year’ s Tony-award winning performance in “Good Night, Oscar,” is brilliantly transformative playing, among others, a writer facing a gigantic writer’s block, a terrifying stalker and the stalker’s twin (all of whom, in the end, may not exist). — Jonathan Dahl

At Studio Seaview, through April 12, 2026; studioseaview.com. Review date: March 8, 2026)