Multiplex

Doctor Danton Black was Professor Martin Stein's assistant during the development of the experimental Hudson Nuclear Power Plant. Shortly before the plant opened, Stein caught Danton stealing plant designs and fired him, but did not turn him in. To cover his tracks, Danton went to the authorities and concocted a story that Stein had stolen the plans for the plant from him.

The Nuclear Regulations Council decided to postpone the plant's opening while they investigated Danton's accusations. Stein, fearing that the delay would cause enough public concern to prevent the plant from ever opening, decided to turn the plant on to demonstrate that his theories were sound. His test, however, was sabotaged by ecoterrorists who placed a bomb in the facility. The resulting explosion caused the merger of Martin Stein and Ronnie Raymond into Firestorm. Ronnie and Stein weren't the only ones present at the plant, though. Danton Black snuck into the plant in hopes to find more evidence to use to frame Stein but was caught in the explosion. After discovering his new powers, Danton Black became Multiplex and fought against Firestorm.