If there's ever a book with a split personality, that book is "Lunar Park."

In his fifth full-length novel, Bret Easton Ellis seems torn between writing a fictionalized memoir and a Stephen King horrorfest, complete with leaf beasties and ghastly bird dolls. He builds up a confusing if compelling storyline, only to have it spill into an unholy mess at the climax.

Bret Easton Ellis wrote a gloriously nihilistic novel called "Less than Zero," sparking off a bestselling career, drug addictions, and a hedonistic lifestyle. A few years later, he's wed to girlfriend Jayne, and living in dysfunctional tranquillity in the countryside with two kids. He's working on a new book, the perpetually pornographic "Teenage Pussy," and still doing lots of drugs with pal Jay McInerney.

Then weird things happen: A bird toy is killing animals. Bret's dad's grave appears. Monsters are invading his house. And a mysterious police inspector tells Bret that someone is emulating the gruesome murders from "American Psycho." And as he tries to keep his family safe, Bret finds that his own fiction is what is spawning all this horror.

"Lunar Park" is an intriguing self-exmination; I can only imagine what spurred Ellis to write it. It seems like an exorcism of the cynical, drug-dealing demons of excess that ran rampant throughout his novels. And in the world of "Lunar Park," those novels -- especially the controversial "American Psycho" -- have an influence on the real world, whether it's bringing horrors to life or inspiring a serial killer. It's a fascinating look at fiction vs. reality.

And despite the literary conceit of having himself as the lead character, Ellis' examination of his fiction is a thorough and brutal one. He even goes down to his writing style. The book opens with him looking back on his books, and noticing how the Spartan style of "Less Than Zero" evolved into babbly rambling. With this book, he's settled into a comfortable middle-of-the-road style.

Unfortunately, Ellis also gets locked into a Stephen King fantasy, complete with a see-it-a-mile-away plot twist right out of "Rear Window." He creates some genuinely chilling moments, such as when his alter ego starts seeing graves and monsters. But by turning all that good horror into self-examination, it loses most of its punch. And as the novel builds to its anticlimax, Ellis doesn't seem sure what to do with the plot threads he's woven together, like the disappearing boys.

Metafiction runs wild in "Lunar Park," a novel split between literary study and total horror. But Ellis seems to lose the grip on his plot, and it spins out of control like the book's events themselves.