Sphere has signed Medlock by S. G. Hartnell, the pseudonym of BP Walter. Medlock is a Gothic horror novel coming out in hardback, trade paperback, ebook and audio on 2 October 2025. Senior commissioning editor Cal Kenny bought UK and Commonwealth rights, excluding Canada, from Joanna Swainson.

Medlock is an atmospheric and disturbingly tense contemporary reimagining of The Secret Garden from the perspective of Mrs Medlock, the housekeeper. ‘1978. Mrs. Medlock is the dutiful housekeeper at Marwood Manor. One of the few remaining staff, she protects a dying aristocratic order, serving the Lord and Lady and caring for their sickly young son. For over the past twenty years, Mrs. Medlock has become the keeper of secrets. Secrets of the family. Secrets of her own. Secrets that may be found in the manor’s walled garden, out of sight but not forgotten. When a distant relative, Mary, arrives at the property in need of a place to live and with a determination to explore, Mrs. Medlock fears the secrets of Marwood are no longer safe. And digging up the past may have deadly consequences for them all…’

Walter/Hartnell has said: “I’m absolutely overjoyed that Medlock has found a wonderful home at Sphere. This book draws on elements of my favourite classic novels, especially The Secret Garden, mixed with a very dark edge of gothic suspense. It’s been a delight to work with Cal and the team on this book and I’m so excited for it to go out into the world next year.”

Kenny said: “Medlock is equally imaginative and atmospheric, terrifying and exquisitely observed. The world SG Hartnell has created is ostensibly the world of The Secret Garden, but so much darker, stranger and more frightening. This is not a retelling but a reimagining, and I feel certain readers will love it. It is the first of many contemporary horror stories that the author was born to write.”

Swainson said: “I’m really excited to see Barnaby take this new direction with Cal and the team at Sphere, who could not have shown more enthusiasm for this novel. Having always tended towards dark and disturbing in his BP Walter novels, as SG Hartnell he has taken this a step further to explore the darkest recesses of human nature in an incredibly evocative way.”

Photograph by Colin Ross