JAMES CRUMLEY strings Dancing Bear with a weird storyline of antics you can scratch your head over, trying to understand why Milo Milodragovitch is trying to kill himself, or you can suspend reality, have some fun and roll with it.

The first-person telling of the story has a pungent masculine air: the wrung-out investigator--actually a rent-a-cop--drinking schnapps and snorting coke to maintain his equilibrium, while he chases back and forth from western Montana to Seattle in search of . . . something or other. With only a few pages to go Milo isn't sure himself what all's been going down.

The plot is there and you'll catch glimpses of it from time to time. It has to do with the transporting of drugs and the illegal disposal of toxic waste material. But Milo's lifestyle is the study. Milo isn't the "Dancing Bear" but he sure moves, caroms from scene to hair-raising scene, defying you to keep up with him.

He's 47, he's raunchy, he's hungover and strung out when he isn't drunk and stoned. Works for Haliburton Security in Meriwether, Montana, somewhere near Butte. Lives alone in a cabin. Eats steaks off a dry cow elk he poached with a crossbow; three dozen oysters for lunch on one occasion. Has gone through five ex-wives and "run out of exotic venereal diseases and disabling prostate disorders."

His wit is usually dry. He recognizes and points out absurdities of all kinds in this life. But his forte is self-destruction. He hits enough lines of cocaine before the last page to tear his nose off. Drinks enough alcohol to explode a healthy liver. But he doesn't even vomit a little blood till page 155. Do you know why he drinks?

"Whiskey for warmth in the guts, for fire to burn the ugly taste of violent death out of my throat," yes, and "whiskey for laughter." Excuses that are as good as any.

It's interesting that the only woman in the book Milo doesn't have sex with--on a kitchen floor here, in a steamy bathroom there--Milo's dad had some 40 years before. This is Milo's client, Sarah Weddington, who's about 70 now.

Sarah is curious about a couple she observes meeting every Thursday in a woods near her house, arriving in separate cars. She hires Milo, pays him well, to find out who they are and what they're up to. Milo begins his investigation by tailing the man through parts of western Montana and into Idaho, the route carefully noted by number, and the story is off with a bang that can be heard in Elk City when a car bomb explodes in the night.

Maybe God does watch over drunks and fools. Milo is believed dead for several days, later in the story, and has every right to be. There is only madness in his madness. His playing dead enables him to get armed to the teeth and go after the bad guys.

The weapons are specific, from a Colt Python to a pair of Ingram M-11 submachine guns. But there's a lapse in the author's research when "a spurt of flame exploded from the end of his arm, followed by the sharp ugly splat of a silenced revolver." A revolver can't be silenced, not with open chambers. Even if it could be, there's no "spurt of flame" from a silencer.

The first-person style, the author's sound, is bigger than life, satirical, and it lets Crumley get away with murder. It allows Milo to say to his back-up man, Simmons, "This is it, lad . . . showdown city."

It permits traditional private-eye images that are graphic if not always original. Some are downright tired. "I dropped her like a bad habit and she fell to her knees like a nun seeking sudden forgiveness." Or "busier than a one-legged man in an ass-kicking contest." "Snow as dingy as a wino's sheets . . . and the sky is the color of snot."

An author might think twice about allowing a character to say, "Damnation, I thought this only happened on TV."

But there's enough energy in Crumley's writing to keep the reader turning pages (never mind the plot), seeking more outlandish excesses, obscenity toppers, unexpected sex, rooting for Milton Chester Milodragovitch III all the way. There is the hope his reward will be, at the least, detoxification. So he can come back again, soon.