Hannah Sampson knows terror. Unseeable, unknowable predators that lurk in the deep. She’s a cop, an expert scuba diver, and leader of the Denver Underwater CSI team. For Hannah, diving is nasty business in polluted lakes and frigid reservoirs where no one is ever found alive. When a scientist is found dead under 70 feet of tropical ocean, Sampson is summoned to the sun-drenched beaches of the British Virgin Islands to investigate. She is fully prepared to face unknowable dangers beneath the crystal-clear waters of an idyllic paradise. But the possibility of murder runs deeper and darker than the sea itself. Whatever the victim was looking for, he found. Whatever he found was the death of him. Now Hannah must discover for herself what lies beneath-a secret that could take Hannah's breath away.