While diving on Jesse Stoker's boat, Cassandra, a local radio personality awaiting contract with extraterrestrials, disappears. Stoker considers her a hoaxster, but allowed the charter because the bank is ready to repossess his vessel. Cassandra's body is found three days later, but the M.E. finds she's only been dead for five hours. Once it's known that Stoker filled her tanks and she died from oxygen poisoning, he becomes the prime suspect.
He's never lost a diver before, doesn't believe in alien abduction, and doesn't believe she just died. To clear his name, stop a wrongful death suit, and save his livelihood, Stoker must figure out where Cassandra spent the missing days and find her killer.