When a young woman washes ashore on a Fort Lauderdale beach, Sloan McPherson of the Underwater Investigation Unit is called in to consult. Sloan’s instinct says murder, but even then, there are too many questions.

For answers she reaches out to Gwen Wylder. The Miami homicide detective is notorious for being manipulative, bitter, a tyrant to her peers, and wicked smart. And she demands something in return from Sloan: fresh insight into seemingly unrelated cold-case murders and disappearances—and a possible serial killer trolling the Florida coast.

As loose ends of the old files begin to come together, another woman disappears. Sloan and Gwen are certain she’s the newest link in a deadly chain. They are determined to track her down before she dies, but they soon find themselves in uncharted waters. And the deeper Sloan and Gwen go, the stranger the case gets.

Published
February 21, 2023
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Underwater Investigation Unit

The series

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The Underwater Investigation Unit series immerses readers into a world where danger lurks beneath the surface of the ocean, and no mystery is too deep to uncover. With its perfect blend of pulse-pounding suspense, meticulous police work, and the eerie allure of underwater exploration, this series presents a unique twist on the traditional thriller. Here, crime doesn’t just happen on land—it thrives beneath the waves.

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The series follows Sloan McPherson, a seasoned detective with a past shaped by the deep blue, as she teams up with former Navy diver Scott Hughes. Together, they tackle some of the most perplexing cases involving underwater crimes, missing persons, and the shadowy world of marine ecology. From sunken wrecks to illegal treasure hunting, the stakes are always high, and the ocean itself is as much a character as the human ones.

In each installment, Mayne takes readers on a journey not only through intricate investigations but also into the heart of the ocean’s mysteries. The compelling plots dig into environmental issues like coral poaching and ecoterrorism, while also exploring the psychological toll of underwater exploration. The unpredictability of life beneath the water’s surface, where the normal rules no longer apply, adds an extra layer of tension to every chapter.

But it’s not just about the crimes. As the series progresses, the emotional stakes grow, deepening the relationships between Sloan, Scott, and the community around them. These aren’t just detectives solving crimes—they’re people with history, who are forced to face their own demons as they dive into the unknown.

Whether it’s a cruise ship bombing off the coast of Florida or a chilling disappearance that leads to a submerged treasure hunt, each story in the Underwater Investigation Unit series is filled with danger, intrigue, and complex, well-rounded characters. Mayne’s meticulous attention to detail, especially with diving techniques and marine biology, adds an authentic touch that elevates this series beyond the typical crime procedural.

For readers who crave something more than just a typical thriller, Underwater Investigation Unit delivers not only a deep dive into suspenseful mysteries but a fascinating look at the unforgiving beauty of the ocean itself. Prepare to hold your breath as you descend into the dark depths of crime and intrigue—where not everything is what it seems, and the ocean's secrets are always waiting to be discovered.

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