A sea-suspense tale with a strong and literally fabulous climax. An ex. South African naval officer, Struan Weddell, is sent to police Possession Island, ostensibly to protect a recently uncovered lost city from pillagers. Looming over the island is a vast arch of natural rock, the Bridge of Magpies, near which a liner was sunk by a U-boat during World War II. Weddell falls in with a girl who was born prematurely on the sinking liner and rescued by an old fisherman who turns out to be Japan's legendary ""Master of the Equinoxes, Lord of the Solstice."" He is the only living master of the Book of Tsu, a text that has guided Japanese naval tactics for 800 years. After the Book of Tsu was secretly transferred onto the U-boat, which in turn was partially sunk by a depth charge, the Japanese navy lost the Battle of Midway, their first disaster ever. The Russians, the Japanese and Weddell are all out to recover the mystical tome from the sunken sub which only rises for a few hours during the annual combination of a particular current and hot wind, and there's quite a night fight to get into the sub before it sinks again or blows up. Solid adventure, great hokum, and a sure-fire flick if it's ever made.