Seamus Moynihan Books in Order

Seamus Moynihan is a second-generation homicide detective working the streets of San Diego, a city that looks sunny on the surface but hides plenty of darkness. He drives a classic Corvette, lives alone on a boat, and has a talent for aggravating his superiors almost as much as he has for reading a crime scene.

In The Serpent's Kiss, Moynihan is confronted with one of the strangest cases of his career, victims dying from exotic poisons and snakebite, their deaths staged with biblical overtones. The investigation pulls him from upscale neighborhoods to zoos and reptile dealers, then on to a fundamentalist snake-handling church where faith, fear, and spectacle blur.

The Second Woman raises the stakes even further. What looks at first like an isolated ritual gone wrong soon reveals a pattern of murders tied to a cult obsessed with ancient sexuality and a puzzle buried in the Book of Genesis. As Moynihan tracks a killer who uses venom as a weapon, he also has to grapple with scholars, true believers, and his own complicated relationship to religion.

Across the books, Sullivan leans hard into the nuts and bolts of a homicide investigation: interviews that go sideways, forensic puzzles, political pressure from above, and the way a single bad decision in the field can derail months of work. Moynihan’s Israeli-born partner, Rikko Varjjan, adds another perspective, and their banter helps keep the stories human even when the crimes grow grotesque.

These are not cozy mysteries. The series features graphic crime scenes, morally twisted suspects, and villains whose beliefs give them terrifying certainty. At the same time, the books also spend time on Seamus’s family, his history as the son of a cop, and the small acts of loyalty that keep him from burning out completely.

You can read the Seamus Moynihan novels in publication order or dip in wherever the premise grabs you. Either way, expect big-city police work colliding with fringe religion, strange science, and the question of how a decent cop holds the line when the cases start to feel personal.