BBC Books has signed short stories from a number of authors including Joanne Harris, Cecelia Ahern and Jake Arnott for a new Doctor Who digital shorts series Time Trips, launching in December to celebrate Doctor Who's 50th anniversary.

Arnott, whose short story will be published in the spring, followed by Ahern and Harris later in the year, said writing his story 'was an opportunity to travel back all those light years ago when I was a kid, full of wonder, watching Doctor Who for the first time'.