Research biologist Jane Marcus senses something bad has happened as she stands on the dock waiting for the overdue floatplane carrying Craig, her young research assistant. Craig has been on the other side of Kodiak Island digging clams that Jane plans to test for the presence of a toxin that may have caused the death of a woman on that side of the island. It is a beautiful day for flying, but the plane is an hour late, and when the head pilot for the air-charter company arrives at the dock to go in search of the missing plane, Jane accompanies him. The pilot assures Jane that the plane is probably stuck on the beach somewhere, but when they fly through a mountain pass, they spot pieces of the plane and debris scattered in a remote valley. Very little remains of the five passengers and the pilot, and investigators soon determine that the plane was blown apart in mid-air by a violent explosion from a bomb placed inside the cabin.
Jane grieves for Craig and feels responsible for sending him on the field trip instead of going herself. She is determined to find out who planted the explosive device that killed her assistant, but to find the murderer, she first must determine who the intended target of the bomb was. The passengers on the plane included a U.S. senator in the midst of a nasty re-election campaign and the senator's husband, a corporate raider with no shortage of enemies. The FBI and Alaska State Troopers focus their investigation on the senator and her husband, but Jane knows that each of the other passengers, and even the young pilot, has at least one person in his life with the means and motive to blow up the airplane, and she convinces FBI Special Agent Nick Morgan to investigate these suspects as well.
Darren Myers, the owner of a salmon cannery was going through a bitter divorce, and his wife, Maryann, admits she is happy he is dead. Dick Simms, the wildlife refuge manager was threatened by renegade guide, George Wall, after Simms conducted a sting operation to catch Wall in the act of breaking several fish and game laws. Jane also learns that Wall served a prison sentence several years earlier when he was convicted of blowing up his girlfriend's father's truck. Bill Watson, the pilot of the ill-fated plane, had a girlfriend who was possessive and demanding and also has a violent streak. She once smashed in the windshield of Bill's truck when he went out with his friends instead of spending time with her. Furthermore, she grew up in the wilderness and was heard talking about how she had enjoyed helping her dad use dynamite to excavate an area of their property. Jane's many questions pull her into the center of the investigation, and soon her own life is threatened.
Since the clams Craig collected were blown up with the airplane, Jane must fly to the other side of Kodiak Island and repeat the collection. She is happy to head out into the wilderness and leave town and the threats on her life behind her, but is she flying away from danger or toward it? Will the mystery of who blew up the airplane follow her?