In the latest installment in Brett Battles’s solid Jonathan Quinn thriller series, he takes us on a diversion back in time. The Damaged is a prequel, telling us what happened before Jonathan Quinn first appeared in The Cleaner.

Jonathan Quinn, if you’re not familiar with him, is a “cleaner.” That is, he’s one of the guys who cleans up the scene after a government agency assassinates or abducts somebody. In The Damaged, he’s still building his reputation. He’s efficient, honest, and thorough in his work. He owes his career –and his life – to his former mentor, Durrie.

But Durrie’s star is in decline. Always a gruff and surly type, recently he’s become erratic. He takes shortcuts at his work, and blames his mistakes on others. His narcissism is devouring his personality.

Quinn wants to help him, both for friendship’s sake, and for the sake of Durrie’s girlfriend, Orlando, with whom Quinn is silently in love. So when he gets an assignment and is asked to take Durrie along as his helper (a demotion for Durrie), he agrees, hoping to help him get his footing again and reinstate himself.

But Durrie has his own plans. In the classic style of bad characters, he’s incapable of believing in virtue in others. If Quinn is helping him, he must have ulterior motives. He must be planning to move in on Orlando.

Durrie is going to thwart this “plot.” And he doesn’t care who gets hurt along the way.

The Damaged was a pretty good story in a dependable series. Its chief defect is a somewhat anticlimactic ending, but that’s because it’s setting the scene for The Cleaner. New readers will find it a decent introduction to the series, and old fans will find it entertaining.