On October 31, 2001, Edward Carnby's best friend and partner, Charles Fiske, turns up dead off the coast of Shadow Island, a mysterious island near Massachusetts. Carnby's investigation soon leads him to Frederick Johnson, who explains that Fiske had been searching for three ancient tablets capable of unlocking an incredible and dangerous power. Johnson begs Carnby to take Fiske's place and reopen the case to recover the tablets, and Carnby agrees, vowing to find his friend's killer.
Johnson introduces Edward to Aline Cedrac, a sharp young university professor, who joins him to recover the tablets and aid Professor Obed Morton — a man she believes to be her father. As they fly over Shadow Island, an unknown creature attacks their plane, forcing both to bail out and parachute down, only to be separated on landing: Edward comes down in the dense forest just outside a manor, while Aline lands on the manor's roof.