The notorious Denver serial killer known as PDQ hasn’t claimed a victim in some 15 years. With sheer willpower, he’s controlled his urges and only wants to live under the radar as a mild-mannered state employee. But when a journalist is killed by someone using his method, PDQ is furious. He wants to protect his “brand.”

So Harry Kugel — PDQ’s real name — contacts Flynn Martin, a disgraced television reporter, and reveals the dead woman was murdered by a copycat.

At first, Flynn dismisses Harry as a nutjob. PDQ must have died or been incarcerated for another crime, she believes. But gradually, Flynn realizes PDQ’s the real thing, and solving the new murder could revive her career. Using encrypted communications to protect his identity, Harry agrees to help Flynn, but only if she promises to keep him a secret. As Flynn begins her search for the real killer, Harry plays a cat-and-mouse game as he chides and threatens. “No Lie Lasts Forever” is a frightening tale of the “pact” between the killer and the journalist.

Mancos, Colo., author Mark Sevens (a former Denver Post reporter) is best known for his stand-alone baseball novel “The Fireballer,” but he honed his thriller creds with his Alison Coil mystery series. “No Lie Lasts Forever” is fast-paced, and Stevens’ look into the mind of a serial killer is chilling.

Despite Flynn’s promise to act alone, she turns to a photographer as well as her father, a retired Denver Post reporter, for help. The police stonewall and refuse even to consider that PDQ wasn’t responsible for the journalist’s death. Even Flynn’s ex-husband, Max, a cop, is skeptical.

A tip leads Flynn to the murder of a Denver man and then to his wife, who fled to Mexico. Flynn tracks down the woman, who confesses that she was driven to the border and provided with a house and job. All this was overseen by a policeman known only as Captain A. Flynn is convinced identifying him will lead to the real killer, but Max can’t — or won’t — tell her who he is.

“No Lie Lasts Forever” might be just a traditional thriller if it weren’t for Stevens’ depiction of Harry. Beneath his dull persona, Harry is an evil, calculating man. Dating a woman who wants a sexual relationship, Harry finds old urges kicking in. He fantasizes about killing her. He’s obsessed with Flynn and angry at her for breaking her promise not to tell anyone about his emails. He begins to stalk her. At a Broncos’ rally, where Flynn is doing a live broadcast, Harry, his face painted blue and orange, stands close enough to touch her. Then he tricks Flynn’s 13-year-old son into letting him into Flynn’s house.

The story will seem all too real to local readers because it is set in Denver. Harry lives just south of Governor’s Park. Events take place in Cheesman Park, Bear Valley and downtown Denver. You can follow Harry’s route as he walks from the state office building to his Sixth Avenue apartment.

He could be any one of the workers you pass on the street every day, men to whom you never give a second thought.

All this adds up to a great read. “No Lie Lasts Forever” is a first-class mystery.

Sandra Dallas is a Denver-based author and book reviewer.