Doyle also learns the target's escort includes a transport ship carrying American prisoners from an internment camp in the Philippines where his wife and child were being held.

After surviving a relentless bombardment of depth charges, the Greyfish returns to base at Pearl Harbor.

Setton then agrees to give the Greyfish "one more trip" to try to sink the Shinaru - but on the condition that Sloan must take the promotion if Doyle fails.

But when the Greyfish is assigned a quiet, out-of-the-way patrol area off the Alaskan coast, Doyle thinks he has been betrayed by both Setton and Sloan, and reveals that he knew about the latter's offer of his own command all along.

An initial encounter with the Shinaru results in the submarine's periscope being disabled and the radio antenna destroyed.

The film had its premiere on October 23, 1958, for Navy and government officials at the Loew's Capitol theatre in Washington D.C.[4] Bosley Crowther of The New York Times was unimpressed, writing, "Stereotypes of pig-boat [submarine] fighting that were stale in Destination Tokyo are played and replayed in this picture as if they were freshly inspired.