The details of the early life of the criminal known as Joe Mimic prior to his appearance in Gotham in 1947.  He was known as a small-time thief but the extent of his criminal career is unknown. One summer weekend, Alan Scott and Doiby Dickles decide to relax at Shoretown, an amusement park on the outskirts of town.  While riding a roller coaster,  they hear cries from the Red Mill, an old mill style boat ride. When the investigate, the find a gang of crooks blockading the path and robbing passengers in the boats as they pass.   Green Lantern and Doiby immediately engage the gang, nagged by a sense of deja vu. The leader of the gang, "Joe Mimic" flees into a hall of mirror and as the heroes try to navigate the moving reflections, Mimic escapes.  Afterwards, they recall a similar robbery at the Red Mill the unfolded just like the one they had just experience other than the added hall of mirrors, which made the crime successful.

Later Mimic retreats to a library to study up on oldl crimes.  He happens upon a robbery at the Steel Works several years before thwarted by Green Lantern when the workers had seen them thieves and sounded the alarm.  In Mimic's revision, the gang disguised themselves as workers themselves, allowing them to get close enough to the office to overwhelm the guard and steal the payroll.  When Green Lantern arrives, the lure him into a trap involved the same loose beam that was an obstacle in the previous crime and render him unconscious.  Stuffing him into a furnace, the crooks leave Green Lantern to die when the fires are lit.

Buried in wood, Green Lantern appears done for but a small path of light through the top of the furnace allows his ring to blow the stop-whistle and the workers turn off the furnace.  Escaping quickly, he goes to find Doiby, who had been promised a "water-cure" being dropped into the Gotham River.  He manages to rescue his sidekick but when Green Lantern returns to the surface, Mimic's gang is long gone.

In a final act, Mimic decides to rob a luxury yacht of three ivory elephants owned by a rich maharajah.  In a prior version of the crime, the thieves left their victims alive, who then called the police.  Mimic decides to murder them, covering his escape.  Before he can, Green Lantern and Doiby leap from the ships air vents and attack them.  As Mimic tries tricks the felled Green Lantern in the previous crime, the hero has also refreshed his memory and modifies his actions to counter him.  Mimic and his gang are then carted off to jail (Comic Cavalcade #22).