The “Leveller” trilogy rounds itself off in a satisfying way in Dan Wheatcroft’s No Room for the Innocent.

This series, as you may recall, involves intertwining plots centered on two main characters – Inspector Thurstan Baddeley of the Liverpool police and a man known as Nicks, who is a top-level assassin dispatched by a high-level, secret government organization to kill the worst criminals the police can’t touch. The two men know each other, and share a grudging respect, though Nicks is always one step ahead of investigators.

But now there’s a problem. Nicks’ handler, Don, has been murdered. Because Don is his only contact in the organization, he’s suddenly out in the cold and vulnerable. When he learns that his controllers have been less than altruistic in their operational aims, he can think of only one person to go to for help – Inspector Baddeley.

The writing in these books is adequate, with occasional grammatical lapses. But the author’s knowledge of police work (he’s a former cop himself) makes the settings and procedures authentic, and I liked the characters a lot.

I enjoyed this series, and recommend it, with only minor cautions for grown-up themes and violence. Conservative opinions are occasionally hinted at.