In the Pacific Ocean, a Silicon Valley magnate vacationing on his luxury motor yacht Carpe Diem, stumbles across a floating island of pumice.

Two weeks later, the motor yacht returns to its home port in San Diego on autopilot – but when it arrives, nobody disembarks.

Sam Reilly and his team are called in to investigate what happened on board Carpe Diem. But what at first appears to be a simple boating accident soon turns into a deadly game of international intrigue – sending America and Russia racing toward each other on an unavoidable collision course.