‘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.