Base Line

by James Ellson

‘Gallops along to a gripping climax. A cracking read.’ (Zoe Sharp)

‘All the authenticity you’d expect from a former DI, but with a command of pace and prose that’s a delightful bonus. Base Line grips from the very start.' (Oliver Harris)

A routine case leads to a Russian cell operating in the UK.
Investigating a tyre blowout on a school minibus is not what DCI Rick Castle had envisaged in his new job in charge of Special Investigations at South Manchester. He’d prefer to be making headway on a cold case murder, and following up leads from his recent press conference.
Then drugs are found in his car, and he’s arrested.
The fourth book in the critically acclaimed DCI Castle series.

300 pages, Paperback

Expected publication June 16, 2026

About the author

James Ellson was a police officer in the UK for 15 years, starting in London and finishing as a Detective Inspector at Moss Side in Manchester. When he left the police he started writing, and has been writing ever since.

James’s debut novel The Trail was published in 2020, and the sequel Cold Dawn in August 2022.

He also writes short stories, and was runner up in the 2021 Bay Tales Christmas short story competition with Roisin's Christmas Party. His story The Translator was published in a 2022 anthology (To Serve, Protect, and Write) of former police officers, now writers.

James is a keen climber and mountaineer, and has visited Nepal many times. In 2004 he climbed 6,812 metre Ama Dablam, and in 2008 soloed the Matterhorn. He lives in the Peak District with his wife, and manages their smallholding, which includes bees and an orchard.