Bishop Blackie Ryan is feeling more than a bit out of place on the USS Langley, an aircraft carrier on duty hundreds of miles from the nearest dry land. But the ship is in trouble--several of her crew have disappeared without explanation, and one dead officer has seemingly reappeared. The captain is a relative of Blackie's boss, Cardinal Cronin. So Blackie, troubleshooter and problem-solver, has been dispatched to the Langley, where he soon finds a mystery as deep--and dangerous--as the ocean.