Chris Knopf’s third novel set in the Hamptons, Head Wounds, continues the adventures of his hard-drinking, existentialist hero, Sam Acquillo.

What initially drew you to the Hamptons as a setting for a mystery saga?

There’s a cottage that looks out on the Little Peconic Bay in my in-laws’ neighborhood in Southampton’s North Sea. I used to play a mind game—what if a semisuicidal burnout lived in that house? Would the stunning beauty trump his self-induced woe or vice versa? This fundamental tension between extremes seemed to naturally extend to other aspects of what Sam calls the “weird social ecosystem of the Hamptons.” I find that very fertile ground.

Sam is a former boxer, an ex-con, a onetime corporate exec, a likely alcoholic with violent tendencies who reads Tocqueville and Kant. How much of you is in Sam?

My father was an Ivy League—educated engineer with a quick wit, nasty temper and penchant for problem solving. So the type exists. As with places, I think people are a lot more interesting when wracked by interior contradiction. I don’t know where I fit in myself. I read Tocqueville and Kant, but so far never socked a co-worker in the nose.

Why did you pick the name of Eddie Van Halen, the aging rocker, for Sam’s dog? And will Eddie be undergoing hip replacement surgery in an upcoming novel?

When my son was little, Eddie Van Halen was one of his imaginary friends. The other was Michael Jackson. I think I chose wisely. As far as Eddie’s well-being, my wife says she likes reading my books because nothing bad will ever happen to the dog.

One of the most remarkable elements in your novels is Sam’s evolving relationship with his girlfriend, Amanda Battiston. Amid all the breakneck action, there’s a profoundly deep story line here.

The pursuit of nasty killers helps revive Sam’s spirit, but so do entanglements with other people, notably Amanda. He could have wallowed in existential despair, but unlike Camus’s Doctor Rieux, it isn’t just the purpose of the moment that sustains him, but a dawning discovery of the transcendent power of human interaction. He chooses to evolve, which I find more interesting than dwelling in emotional stasis. This sets the course for the books as well, which also evolve. Sam and a regular supporting cast return in each—they’re familiar, but not unaffected by the passage of time and changes in circumstance. This is more realistic, and I hope more involving, for the reader.