Hoping the adventure of a raft trip in Big Bend National Park will lift her spirits, Paul takes Anna to southwest Texas. Instead of the soul-soothing experience they'd longed for, the couple finds a pregnant woman--more dead than alive--and soon they are sucked into a labyrinth of intrigue that leads from the Mexican desert to the steps of the Governor's Mansion in Austin.

A grandmother in her sixties emerges from a mental fog to find she's trapped in her worst nightmare. Rose Dennis wakes up in a hospital gown, her brain in a fog, only to discover that she's been committed to an Alzheimer's Unit in a nursing home. With no memory of how she ended up in this position, Rose is sure that something is very wrong. When she overhears one of the administrators saying about her that she's "not making it through the week," Rose...

Anna Pigeon, a ranger for the U.S. Park Services, sets off on vacation--an autumn canoe trip in the Iron Range in upstate Minnesota. With Anna is her friend Heath, a paraplegic; Heath's fifteen-year-old daughter, Elizabeth; Leah, a wealthy designer of outdoor equipment; and her daughter, Katie, who is thirteen. For Heath and Leah, this is a shakedown cruise to test a new cutting-edge line of camping equipment. The equipment, designed by Leah, will...

When four young employees of Yosemite National Park disappear, ranger Anna Pigeon goes undercover as a waitress at the Ahwahnee Lodge to investigate. Living in the staff dorm, she soon discovers there's a connection between at least one of the missing girls, a crashed plane containing a fortune in drugs, and the outsiders who've moved into the tent cabin last occupied by a skilled climber who's also among the disappeared. The first attempt on her...

While studying grizzly bears in Waterton/Glacier National Peace Park on the border of Montana and Canada, ranger Anna Pigeon finds herself in the midst of a series of deadly bear attacks that leave her struggling to re-evaluate her own view of nature.

When park ranger Anna Pigeon stumbles on the corpse of a girl with a noose around her neck, she is plunged into a murder investigation with serious racial overtones in the heart of the Deep South.

Soon after Anna Pigeon joins the famed wolf study team of Isle Royale National Park in the middle of Lake Superior, the packs begin to behave in peculiar ways. Giant wolf prints are found, and Anna spies the form of a freat wolf from a surveillance plane. When a female member of the team is savaged, Anna is convinced they are being stalked, and what was once a beautiful, idyllic refuge becomes a place of unnatural occurrences and danger beyond the...