The first script reading for the new ABC sitcom The Geena Davis Show was anything but a barrel of laughs, according to co-star Peter Horton. The actor ? best known for his dramatic roles on thirtysomething and Brimstone ? says he simply wasn't prepared to try his hand at comedy when executive producer Nina Wass called him with the job.

"I never really just thought about doing a sitcom before," he confesses of Geena, which will air Tuesdays at 9:30 pm/ET. "I was rather nervous about it at the beginning."

But Wass was so convinced that Horton was the right man to play opposite Davis that she simply put the two of them in a room together and told them to start reading. Horton, hired to play the love interest of Davis's single mom character, says the first run-through was terrible.

"I said, 'Let me do it again,' " he recalls. "So we just started to work on it. Pretty soon it got to be really kind of cool, and we started to have fun. The whole experience ended up being a really great one."

Horton also discovered one of the big perks of doing a sitcom: the light schedule. "I [can] at least develop things and write things... in a way that I couldn't if I was doing a long-form dramatic series," he says. "Plus, I had a baby. So all of that sort of seems to fit together well."

Still, Horton better not get too comfortable at his new gig: Davis, an amateur archer, has joked that she plans to do some target practice on the lot. Notes the thesp: "She did get me a T-shirt recently with a big target on the back."