The on-sale date is from the publication date recorded in the Catalog of Copyright Entries, Part 2, Periodicals, 1944, New Series, Vol. 39, No. 4, p386.
Atlanteans (guest-star); Gralt (Atlantean, introduction); Og (Atlantean, introduction); Professor Deems (introduction); Miss Deems (introduction); Kurt (villain, introduction); Nazis (villains)
Synopsis
Sub-Mariner returns to his people and finds that Nazi subs have located them and have been dropping depth charges on them. He tracks them to a base in the Antarctic and has his men bomb them. He saves an American and his daughter from the onslaught and learns that the Germans were squirreling away supplies to make a comeback after their foreseen defeat.