Carole and John Barrowman preparing for a U.K. book promotion event. Photo courtesy of John Barrowman Official/ Facebook

CARDIFF, Wales, May 11 (UPI) -- Actor and author John Barrowman is teasing his upcoming return to Cardiff, Wales -- the setting of his iconic sci-fi series Torchwood.

The Scottish-born, America-raised star was in Cardiff last week to promote Conjurer, the latest book he penned with his sister Carole.


After leaving a signing event, he posted a quick video on Facebook, thanking the city for its support.

"Thank you very much, Cardiff," John said in the 16-second clip. "That was awesome. Loads of people showed up and bought books and we hope you love it. We're going back to London now and I'll be back in Cardiff in about a week and a half, but I'm not telling you what for."

Carole, sitting in the backseat of the car, joked, "I'll tell you!"

"Shhhhhh!" John said before turning off the camera.

Torchwood, a Doctor Who spinoff, ran four seasons 2006-11. The actor played Captain Jack Harkness, the leader of a small team of alien hunters, in the show.

John is now a cast member of TV's Arrow.