The adventures of Captain Jack Harkness, the alien-hunting hero of Doctor Who spin-off Torchwood, are to be continued in comic form by the actor who played him, John Barrowman.

Co-written with his sister, Carole E Barrowman, the actor’s new comic series will see Captain Jack back in Cardiff and looking for the help of Welsh police officer Gwen Cooper in combating “a dark technology from a forgotten species [which] has been claimed by a conspiratorial power”, said publisher Titan Comics.

“In this collision between an ancient civilisation and an all-new evil, the Earth itself may be forfeit,” said Titan of the new series. “Only Jack, Gwen, and their allies from what remains of Torchwood hold the key to stopping a cataclysmic wave of destruction … On the road, on the run and under fire – can Jack and Gwen put aside their differences and rebuild the heart of Torchwood … before its flame is stamped out forever?”

The Torchwood TV series, which aired from 2006 to 2011, was an adult spin-off from Doctor Who, with Captain Jack, a bisexual former intergalactic time agent from the future now heading up the Torchwood Institute, charged with protecting the Earth from extraterrestrial threats.

Jenny Colgan, the bestselling author who has also written a number of Doctor Who novel and short stories, welcomed the news. “I love John and his ongoing involvement with everything Torchwood. I miss him in the show; he brought so much lightness to it,” she said, adding that the universe of Doctor Who was “a pretty addictive world to be a part of, and very hard to let go ... You can see it with David Tennant and Catherine Tate coming back to Doctor Who this year.”

The Barrowmans’ new comic series will be an official continuation of the Torchwood saga, said Titan, and will be in continuity with Big Finish’s Torchwood audio dramas. Out on 6 July, it will be illustrated by Antonio Fuso and Pasquale Qualano. Barrowman has previously co-written an Arrow comics series with Carole E Barrowman, published by DC Comics earlier this year, as well as a Torchwood novel, Exodus Code, also co-written with his sister.