Broadchurch series 2: Plot clue hidden in new spin-off book

'It's something only the die-hards will pick up on' says author Erin Kelly

The Broadchurch 2 cast read through Chris Chibnall's 'brilliant' new script ahead of shooting (ITV)

A clue to the twists and turns which will be revealed in the next series of Broadchurch has been inserted in a new book accompanying the award-winning drama.

Series two of the ITV murder-mystery series, which captivated 10 million viewers, is currently being filmed in West Bay, Dorset.

Whilst the plot is strictly under wraps, Chris Chibnall, Broadchurch creator, has inserted a clue in a spin-off novel, penned by thriller writer Erin Kelly, published next month.

“About three days before we went to press, Chris put in one tiny little clue about something that happens in series two,” Kelly told Radio Times. “It’s something only the die-hards will pick up on, but there’s one line quite early on in the book that won’t make sense to anybody.”

The author believes Broadchurch obsessives will find the clue. “There’s one little phrase in there – I‘m going to be checking out the chatrooms to see if people have picked up on it. It’s just something that’s very playful that he (Chris) did right at the last minute," she said.

The author of The Ties That Bind and The Poison Tree is surprised at the attention lavished upon the series: “You tend to get this level of detail when it’s fantasy or science fiction but when it’s a straightforward classic British murder drama it doesn’t usually attract that kind of fanaticism.

David Tennant and Olivia Colman, who played detectives investigating the murder of a young boy, are joined by newcomers Charlotte Rampling and James D’Arcy in the new series.

Chibnall has the plot for Broadchurch 2 mapped out on whiteboards in an office in his Dorset home. “You have to be very methodical. It’s like a mathematical puzzle where you put all these blocks together and move them around for the most satisfying thing,” he said.

The Broadchurch cast have also been sworn to secrecy over the plot. Chibnall said: “We’re very strict. I’d love people to know as little as possible about it when it airs on ITV. I want you to follow the story when I’m telling it, not before.”

Tennant reprises his role, with an American accent, in a Fox remake of the Bafta-winning drama, called Gracepoint.