Gist Miller, a crewmember of the salvage trawler, Monte Cristo, receives two visits from a ghostly apparition while searching for sunken treasure off the Florida Keys. Soon after the visitations, Gist and crew experience even more strange phenomena as they venture deeper into the bounds of the Triangle. Methane deposits, sea-life, and piracy soon become the least of their worries as they discover the real danger lurking behind the mystery of the Devil's Triangle.

In the climactic finale of Devil's Triangle, Gist Miller and what few are left of the original crew scramble aboard a purgatorial prison posing as a cruise ship set adrift. When Master Mahan, the ancient demon hell-bent on upgrading bodies, brings their pursuit to a head, Gist and friends must abandon their futile flight, and stand to face him. But lurking amidst angry phantom and zombie sailors, an even greater threat awaits them on the pitching deep a threat spanning to biblical times. Caught up in a twister of good versus evil, Gist must find out what it really means to face the devil or lose everything he loves.