A MYSTERY AT SEA plunges forensic geologists Cassie Oldfield and Walter Shaws into deadly waters.

When a boat is found deserted off the California coast, it looks to be a simple fishing accident. But there is nothing ordinary going on here. The geologists track the strange incident to an even stranger project. Someone with toxic skills is at work in this sea.

Cassie and Walter are forensic pros--but they are up against a master in an undersea world where they don't belong. They must face their deepest fears in order to end this project.

If they fail, lethal creations will be unleashed.

Unstoppable.

- All books in the series are complete novels, and can be enjoyed in any order.