The on-sale date is from the publication date recorded in the Catalog of Copyright Entries, Part 2, Periodicals, 1945, New Series, Vol. 40, No. 2, p164.
Betty Dean; Arnold (villain, introduction); Mimi (villain, introduction); Dick Grover (villain, introduction, death, flashback); Ted Wilson (introduction)
Synopsis
Sub-Mariner helps out a friend who is being blackmailed because he thinks he shot his business partner during a struggle over a gun, but it turns out that his fiance shot him and she and the blackmailer got together with the scheme to bleed him of his money by passing the death off as a suicide and keeping quiet about it.