Imagine a version of Alfred Hitchcock's Strangers on a Train in which Robert Walker suddenly sprouts fangs, or Interview With the Vampire reconceived as a pungent, contemporary dark comedy, and you may begin to get an idea of the contradictory pleasures of David Martin's new thriller Tap, Tap, a suspense/horror novel as peculiar as its title is evocative. Here's the clever setup: 36-year-old Roscoe Bird (nice, bright, good guy) and his wife, Marianne (nice, bright, grad student in psychology), are interrupted at home one evening by a knock (tap, tap) at their door. Their caller: Peter Tummelier, ''a short and slightly built man under (a) ridiculous homburg hat (with a) mouth so small and delicate as to be girlish.'' Their mistake: They invite him in.
Peter, it turns out, is a childhood friend of Roscoe's who still seems to be nursing an unrequited crush on him and has come up with a unique plan to woo his old pal he's going to murder all of Roscoe's enemies. In fact, he's already begun; when Peter first comes a-tapping, on page one, the sound precedes the slaughter of a middle-aged couple who may have been responsible for Roscoe's father's suicide. Any allusions to Poe's ''The Raven'' are intentional; quoth Peter as he wipes his lips, ''Nevermore, motherf---er.'' Peter is a vampire, or thinks he is, and if you think the story is getting complicated, wait until you meet the psycho genius who has escaped from a mental institution, not to mention Dondo, the two-foot-tall porcelain doll that has a mind and voice of its own, plus the taste for homicide that appears to be a requirement for admission to this novel's cast of characters.
David Martin is trying to do a lot of different things in Tap, Tap, none of which will please readers who dislike seeing red blood and black humor splattered on the same palette. With a chilly, relentless style that invites both fascination and detachment, he keeps two stories at full boil, one an account of a decent guy trapped in a wrong-man scenario (yes, Roscoe will get in touch with his violent side by tale's end), the other a portrait of a prissy, Eurosnob vampire trying to satisfy his appetites in a brutish world. And he leavens the narrative with twists that amount to very clever sick-jokes (one involves confusion over the word fillet; another is capped by the unspeakable-in-context punchline ''It's something I ate''). Taste yardstick: If Pulp Fiction was not your cup of entrails, skip this one.
For those who can (and want to) stomach it, though, Tap, Tap offers a fable of revenge served up in cold, expertly gruesome prose. As Martin proved in his wholly original suspense novel Lie to Me, he can be a storyteller of malevolent skill; indeed, almost every chapter in the first third of Tap, Tap begins with a surprise a shift in location, or mood, or narrative voice. And Martin's witty, nasty take on vampire culture is far more entertaining than the sodden-velvet prose and self-entranced eroticism of Anne Rice novels. (He's also generous with his blood-guzzling scenes; each victim is deftly drawn, then scratched out.)
What Martin can't do is reconcile one side of Tap, Tap's conceit with the other. A novel of psychological suspense depends on logic so ineradicable it becomes an ever-tightening screw. A horror novel relies on the spooky, the unpredictable, the unnatural. A novel that tries to do both winds up feeling like a cheat, a pitfall into which Martin stumbles whenever he interrupts Roscoe's human-scale story for a big special-effects number involving Peter. (That porcelain doll isn't his most brilliant moment either.) But it's a tribute to the ruthless effectiveness of Tap, Tap that until its last page which manages to be creepy, pathetic, and highly romantic you hang in, hoping that everyone's incisors will go back where they belong. B