A long-awaited vacation in Cuba should be exactly what Ethan needs after nearly losing everything. No cases. No threats. Just sun, sand, and precious time with Tessa. But when a local historian's tales of mysterious ships and hidden caves catch his attention, Ethan can't resist diving into one last investigation—one that could finally reveal the truth about a legendary vessel he's been hunting for years. Meanwhile in Miami, what starts as an innocent Civil War reenactment turns deadly when Agents Marcus Baker and Robbie Holm discover someone has replaced the prop weapons with real firearms. As they race to uncover who would go to such lengths for revenge, they'll need all hands on deck—including the enigmatic Agent Reeves—to prevent history from repeating itself in the deadliest of ways. Two cases. Two cities. And a dragon's worth of secrets waiting to be unleashed.