At some point in the future of the Earth, there is a great metropolis ruled by an elite who force the rest of the adult population to work like slaves operation the machinery that enables the city to function.
However, a rebellion of the workers was being organised, led by a woman named Maria. The scientist Rotwang created a robot resembling a human woman, and then disguised her so that she looked exactly like Maria. Rotwang then substituted this false Maria for the real one, hoping thereby to sabotage the rebellion.
BUt Rotwang's plan failed. The robot was destroyed and the real Maria was free to lead a sucessful rebellion.
Rotwang was believed dead, but actually he had gone into hiding. He decided to try to change history so that the rebellion would never succeed. He rebuilt the robot and sent it back in time to 1942 in order to alter history so that Maria would never exist.
The robot arrived in 1942 somewhat damaged, but made its way to the HQ of the All Star Squadron. There the robot attacked Firebrand (Danette Reilly), thus provoking a battle with the rest of the Squadron. Identifying with the humanoid robot, Robotman came to its defence and took it to his laboratory. There he and his assistant Chuck Grayson repaired and even partially redesigned the robot, whom Robotman named Mekanique.
Mekanique claimed to be from the future,and to have been sent back in time in order to alter history and prevent a devastating war from occuring. Mekanique stated that a car accident was a bout to happen that would set in motion the chain of events leading to the war. Firebrand and Alan (Green Lantern)Scott prevented the accident from happening, saving the lives of military strategist Admiral Higby and a little girl named Annie.
However, in preventing the accident, the two heroes somehow prevented Maria's birth - thereby accomplishing Mekanique's true mission. Mekanique was later reactivated by Commander Steel, who had come to believe that his grandson Steel and his then colleagues in the Justice League had become criminals. Mekanique became Commander Steel's ally and the Commnader managed to pursuade the Members of Infinity Inc to attack the Justice League. The Commander and Mekanique later turned on Infinity Inc. but Steel overcame his grandfather in battle and Mekanique vanished.