"Black Heart on the Appalachian Trail," by T. J. Forrester Illustration by Kristian Hammerstad If you're one of the many readers who recently devoured Cheryl Strayed's hiking memoir, "Wild," your interest may be piqued by the title of T. J. Forrester's new novel, "Black Heart on the Appalachian Trail." Trail books like "Wild" and "A Walk in the Woods," Bill Bryson's classic take, tend to mix in common ingredients: offbeat characters, funny anecdotes, well-chosen details, warm epiphanies. It falls to me to stop you at the trailhead. This is not that kind of book. T. J. Forrester is a novelist whose characters survive on the margins. They hustle, deal, do a little time, pick up work here and there, enjoy booze and drugs, kick booze and drugs, relapse. Their childhoods were things from which to flee. Forrester's first novel, "Miracles, Inc.," recounted the story of a pot-smoking carny who rose to glory as a televangelist only to end up on death row. In "Black Heart," he takes three down-and-outers and sets them a-walking. Their thru-hike doesn't turn out like Cheryl Strayed's. Taz Chavis is a young man doing a short stretch for selling coke. While in prison he reads books about the Appalachian Trail. If I thought hard enough, I could transport myself to the mountains and spend hours a day with an imaginary pack on my back and an open trail in front of me. Once sprung, he chases that dream. "I will walk the Appalachian Trail end to end," he decides. Or die trying. A couple of days ahead of him is Simone Decker, a young woman with a troubled psyche and a fiancé she's ready to ditch. "The time on the trail was supposed to bring them closer together," Forrester writes, "but the opposite has happened." That's Day 2.On Day 4 she takes care of business, removing her ring and tossing it off a cliff. "You can catch a ride into town back on that highway," she tells her heartbroken beau. The third player in the set is Richard, an older man who claims Native American heritage. Richard wears his hair in a braid and sports a bear tattoo on his neck. All three are hiking as a kind of 2,160-mile cleanse. Taz sees the woods as a great place to kick his habit. "There's no dealer setting up in the mountains," he says. It's a dope-free zone. Simone hit the trail "because she's convinced herself that no one can thru-hike the Appalachian Trail and be the same person as when they started. She hopes change will arrive like an erupting volcano, melting her genes so completely that when they cool she'll become someone else entirely. Richard's a boozer, but alcohol's so easy to come by in the small-town way points that he almost never gets sober . . . if sober is what he was after. Forrester has thru-hiked the Appalachian Trail himself, and he has a good feel for its rhythms and social mores. He's no Bill Bryson, but he has his moments of humor. During their initial meeting, Richard gives Taz some advice on campsite flirting. If you want to get lucky on the trail, he says, you'd better come up with some New Age, nature-loving rap. The next time a comely hiker asks for his story, Taz has his answer ready. "I'm a Druid," he says. I'm out here to sleep under oak trees and gain power from the forest. Well played, young man. On Day 9, the first murder victim shows up. Taz and Richard discover the lifeless body of an elderly hiker caught in a tree at the foot of a high cliff. They don't suspect foul play. It looks as if the old man slipped and fell. Instead of reporting their find, Taz and Richard steal $80 from the dead man's backpack and burn the body. More dead people turn up. A missing girl in western Virginia. An elderly woman in New Hampshire. All found crumpled and broken below cliffs. Forrester's reader knows from early on that these are likely victims of Simone's homicidal urges. But Taz and Richard are so bereft of wit and clue that they don't notice the bodies hailstoning around them until their last day on the trail. Bruce Barcott is a contributing editor at Outside Magazine.