"Secret of the Double Death-Wish!"
Clark Kent and Bruce Wayne each receive vivid day-dreams warning them of their alter-ego's impending doom. Given specific directions, Superman and Batman arrive to save each other, and find themselves under attack.
Superman finds himself attacked by four of his biggest enemies, while Batman is assailed by a red robot and numerous bats. After they narrowly escape these situations, they find each other, realize the elaborate trap they are caught in and decide to work together.
As they are about to discover who is behind the elaborate ruse, they find themselves attacked by their parents. Fearing their impending death, both heroes start to spill each other's secrets.
Suddenly a panel opens and we learn that these were actually androids, being tested by Batman and Superman. Everyone agrees they can not work properly, and they are deactivated.
"Zero Hour in the Silent City" reprinted from Green Lantern (1960) #12.
Note: Robin does not appear in either story. Thomas Wayne, Martha Wayne, Lara, Jor-El, Brainiac, Toyman, Lex Luthor and the Prankster are all illusions.