At least novelist Derek Haas is honest.

“I told you not to like me,” says Columbus, the protagonist of Haas’ series of Silver Bear thrillers, moments after yet another of the contract killings by which he’s made his name internationally. And that’s just in the first chapter of the series’ latest book, Columbus. For better or worse, there’s no mistaking the type of guy you’ll be spending the next 260 pages with.

Columbus is just the latest factor in Haas’ master plan: to craft characters with a wretchedness so refined, so incorrigible and so sincere that it’s kind of impossible not to fall for them. With his screenwriting partner Michael Brandt, Haas has explored the vagaries of Old West outlaws (3:10 to Yuma) and the scientific rigors of bullet-bending (Wanted), establishing compelling dramas around bad guys (and gals) who otherwise define the term “antisocial.” And now, with Columbus and last year’s predecessor, The Silver Bear, Haas the novelist takes his title character—and the reader—one step further by yanking down the barrier between antihero and audience.

“What I love about this character and why it stays with me is because he’s a dark man—an assassin,” Haas told me recently from his home in Los Angeles. “But just when you want to disapprove of him, he does something likable and winning. It’s a challenge as writer to say, ‘I’m going to write this in a first-person voice as a killer, but by the time this book is through, you’re going to like this guy.’ To me, that’s what’s exciting.”

The technique is a nifty modern riff on pulp-fiction landmarks from The Killer Inside Me to Elmore Leonard’s original short story “3:10 to Yuma.” In the shadowy orbit of fences (the middlemen who pass along his assignments), marks (his targets) and various other sketchy types encircling Columbus, you’re not really liking him so much as appreciating his cool calculation under deadly pressure. It doesn’t hurt that he’s actually the one hunted throughout much of Columbus, leaving him as the only person shielding readers from even more ruthless murderers in Paris, Brussels, Rome and beyond.

That makes the narrative stakes higher than those in The Silver Bear, an origin story introducing Columbus as a man doing virtually all of the stalking himself. But whatever sympathy that costs him is compensated for by the questionable character of those he’s been dispatched to kill: Boston crime lords, fellow assassins and ultimately a cutthroat presidential candidate with an intriguing connection to Columbus himself. Their time spent in Columbus’ aim entitles him (and us) to a persuasive moral relativism.

Even more essentially, Haas plays with the ideas of work and identity. Cold-blooded as Columbus is, perhaps nothing is more sympathetic than his workaholic drive as assayed in both novels. After all, “silver bear” is nothing more than parlance for a first-class international assassin. He could just as easily be a renowned, in-demand architect or chef.

“When you’re writing about somebody like a hit man and a contract killer, and then you say to your readers, ‘I’m going to make you relate to this,’ you have to find those universal truths,” Haas said. “And that’s what he is doing. He’s trying to strive for A.) the one thing he’s found in his life that he’s good at, and everybody goes through life trying to discover that thing. And then B.) to be the best at what you do. Even if that is killing, you can relate to it.”

As such, it may seem appropriate that the bloodiest casualties in Columbus’ life are romantic. This is what Haas means when he talks about the cusp of disapproval, whether it’s the purposefully bruising end of Columbus’ relationship with his young sweetheart in The Silver Bear or the knowing, guilty endangerment of his Italian crush in Columbus. In the latter novel in particular, Columbus’ work strikes a nerve so deep that even another eight-figure fee won’t likely be enough to numb it. By the time Columbus meets Risina, the sexy Roman bookseller who earns the rare privilege of his confidence, a life after contract killing doesn’t seem as far off as it did when we met him. And of course, if there’s anything that can humanize a hit man in a reader’s eyes, it’s to see him waylaid by love.

Yet one senses that Columbus isn’t ready to give up his Glock quite yet. Haas won’t try to convince you otherwise, either. “From a writing standpoint it’s a fun dilemma to give your main character,” the author said. “Especially when it’s kind of a selfish thing to say, ‘If I bring someone into this, they may be hunted and not even know it.’”

But considering how Columbus’ failure to love (and, moreover, to be loved) fueled so much of his ruthless ambition in the first place, it raises a crucial question for Haas going forward: Can a happy hit man be a productive hit man? Can Columbus actually be too likable?

Haas isn’t saying either way, looking forward instead to his antihero’s third adventure in 2011. “I don’t want to make him just a shark swimming through the water—a killing machine,” he said. “He’s a human being trying to make sense of this game and this world.”