All-Winners Comics #17

The Black Phantom is terrorizing the Mississippi river with a crimewave conducted from a boat covered with mirrors so it can't be seen on the water. During a tussle, Namor pulls back his cowl and gets a look at his face, and believes him to be a guest at a party that Betty and he are attending. Later, after capturing Namor and Betty, the Black Phantom reveals himself to be the twin brother of the party guest. Namor breaks free and pursues the Black Phantom, but the evil doer tries to scare Namor away with TNT and only succeeds in blowing himself up.