The Rule of Threes
The fifth book in the critically acclaimed DCI Castle series.
A protected witness goes missing and leads DCI Rick Castle to investigate an organised crime group.
'Intelligent and pacy thriller'
Paula Hawkins on The Trail
In South Manchester… duty doesn’t take days off.
Days before his wedding, DCI Rick Castle is pulled into the one case he can’t refuse – finding a missing protected witness who could finally bring down an untouchable Mancunian crime lord.
The trail leads him to the desolate Scottish Highlands and explodes into violence and conspiracy, revealing a suspected leak within the police. But the closer Rick gets to the witness, the closer his family gets to danger, turning his obsessive investigation into a battle for survival. If the case doesn’t break him, they’ll go after the one thing that will.