The Glasgow-born Torchwood star, currently appearing in Clyde Auditorium panto Robinson Crusoe, has teamed up with his writer sister Carole to pen the fantasy novel Hollow Earth.
Glasgow's Kelvingrove Art Gallery and Museum and the Pencil Monument near Largs feature in the book, which is set on a Scottish island.
John and Carole started life in Mount Vernon but moved to America with their parents when they were children.
Their story about 12-year-old telepathic twins is expected to be a big hit with fans of fantasies such as Harry Potter and Twilight. Matt and Emily Calder have powers which mean they can bring art to life and even become part of paintings.
But the story sees their abilities sought by villains who want to access the terrors of Hollow Earth, a place where all the demons, devils and evil creatures ever imagined lie trapped for eternity.
The action sees the twins flee from London with their Scottish mum to the fictional island of Auchinmurn, which the authors say is based on Great Cumbrae, and its smaller sister, Little Cumbrae.
Carole re-visited the area last summer and the name Auchinmurn is a tribute to her and John's Scottish gran Murn.
John said: "Both of us were really close to our Gran Butler – Murn, as we called her – and her sister, our Auntie Jeannie.
"When we lived in Scotland and our mum and dad went out on a Saturday night, Murn and Jeannie would watch us. Both of them loved to dance, play games, and we'd always have a good laugh together.
"The island where most of the novel takes place is a real place off the coast of Largs - but we changed the geography and name."
l Hollow Earth by John and Carole E Barrowman is out on February 2.