By David Thewlis. Penguin Canada, 342 pp, $24, softcover

Actor David Thewlis is probably best known for his role as Remus Lupin in the Harry Potter films. (Mike Leigh fans will remember him as the lead in 1993's Naked.) Reading his debut novel, The Late Hector Kipling, is a lot like watching a performance that starts with great promise before veering out of control. At its best, it's a devastatingly witty skewering of the London art world. At its worst, you feel like throwing the book across the room.

Still, you have to admire the fact that Thewlis is so relentless in exposing the many distasteful traits of his title character. A successful artist who paints "big heads" on giant canvases, Hector Kipling is your classic passive-aggressive wanker. Despite the fact that he has loving parents, a devoted girlfriend, and interesting friends, the unappreciative Hector is determined to self-destruct. He ignores his ailing father, betrays his girlfriend by plunging into an affair with a sadistic poet, and lets envy destroy his relationship with his best friend Lenny, a red-hot artistic rival. Worst of all, Hector is constantly questioning his lack of character while steadfastly refusing to change.

At first, there's genuine satisfaction in watching Hector get comeuppance. (If there's anybody who deserves to get his nipple scorched by an unhinged mistress with a Zippo lighter, it's this guy.) It's a tribute to the author's bracing dialogue and deft satirical touch that we manage to put up with Hector's incessant whining for so long. But by the time Thewlis overloads his climax with several bleak scenarios (including a dapper psychopath obsessed with killing Hector) we just want it to end. It does, in the most unconvincing, unrewarding of ways. But closure doesn't come nearly soon enough.