Quest to Break Free of the Horrors of Life : GOING TO THE SUN by James McManus, HarperCollins, $23, 342 pages

The narrator and heroine of James McManus’ fourth novel doesn’t announce herself as Herman Melville’s Ishmael did: Call me Penny Culligan. Instead, she begins: “This isn’t really a horror story.”

Then, for the first 43 pages, she tells us a horror story. Seven years ago, camping in Alaska with her boyfriend, David St. Germaine, she saw him half eaten by a grizzly bear.

Blinded and dismembered, St. Germaine begged to die, and Culligan, a diabetic, obliged him with a shot of her insulin.

Since then, she says, “the thought of what happened . . . of what I did . . . has burned in my blood like cold powdered glass for an hour or two every day, sometimes all day and all night. . . . I can’t make myself not remember it.”

The last 300-odd pages of “Going to the Sun” are Culligan’s attempt to persuade us, and herself, that horror isn’t everything; that her life might have been written by Samuel Beckett, the subject of her unfinished doctoral dissertation, rather than by Stephen King.

Beckett gets much mention here. He “refuses to assume that everybody is young and beautiful and healthy,” Culligan notes approvingly. “He assumes just the opposite: that the loss of one’s health is a given.” He writes about “the comic and cosmic inevitability of the deterioration of the body--about accepting, even wishing for mortality.” She reads him, she admits, because “I want to inhabit a fictional universe in which I am normal.”

There isn’t a word about Melville anywhere. But wait:

Culligan sets off on a bicycle trip from Chicago to revisit the campsite and hospital in Alaska where the horror took place. Monitoring her blood sugar, her credit-card balance and her hyperactive conscience, dodging 18-wheelers, thunderstorms, would-be rapists and her faculty advisor, a lesbian who is in love with her, she pedals west along the Canadian border in search of . . . the Great Brown Bear? No, rangers killed the bear. Something more ghostly, symbolic of the death-in-life that is swallowing her. Might as well call it the Great White Whale.

Now, if the Pequod had dropped anchor in Tahiti during its pursuit of Moby Dick, would Ahab have called off his fatal quest? Probably not. Only if the grass-skirted maidens there somehow matched the emotional impact of the beast that had mauled him.

McManus (“Chin Music,” “Out of the Blue”) creates exactly this combination of menace and allure in the person of Ndele Rimes, who gives Culligan a lift in his Mercedes 500 SL after she breaks a wheel in rural North Dakota.

Rimes is African American and very large. He claims to be a basketball player for the Seattle Supersonics, sidelined by a knee injury. He also carries a gun and could be a carjacker and killer. He summons up any number of stereotypes and fits none of them, as far as she can tell. He comes and goes unpredictably. He makes love to Culligan--as well as St. Germaine ever did.

Rimes is either another nightmare or too good to be true. Each of these possibilities alone is enough to crack her stoicism; together they bring her to the point of collapse.

And none too soon. McManus isn’t really a horror writer. His strengths, rather, are in voices, crowded scenes that spin out of control, observations of the road, an edgy comedy of manners--but something has to happen at the end to balance that beginning.

It happens in a surprisingly undefined way. For the angry, vulnerable Culligan whom McManus has made us believe in, this is appropriate. After all, her memories and her disease (the author is also a diabetic) have forced her, more than most people, to confront life’s limitations; it’s in breaking free of these, if only for a moment, that she can finally define herself.

Call her--”before I am dead,” she predicts buoyantly, with three pages to go--”a notorious writer and a thoroughgoing babe.”