Harold Cosgrove somehow gained the power to move at superhuman speeds. The exact method as to how is unknown as he at different times has given different reasons why (for example super powered foods or mercury mixed with electricity). Like many people with powers, he chose to become a supervillain and used his powers to commit crime. However, like other superpowered beings, he was captured by General McCandless's Number of the Beast VR program. For years, he was trapped in a virtual city. He continued to do what he had done for so long and fought against the herogroup of the Paladins. However eventually the program gathered the remains of the High and with help from his friend the Eidolon things took a different approach. The City began to be plagued by different biblical-like events and even the Four Horsemen of the Apocalypse appeared, with Eidolon being death. These events made Harold change his perspective on life and he began to use his powers to save lives.
When the High started killing the people in the city, to free them Hotfoot was told to stop a Lieutenant Welles from killing everyone in the bunker. After finding their costumes, the Paladins got into a fight with The Authority. However the fight ends, when Welles explains the situation and reveals that the clones of the High called the Reapers have been let lose. They attack the Carrier along with the rest of the world and cause mass destruction. Hotfoot vibrates through one of the clones to destroy it and died along with it only saying "later".
Harold has the power of super speed and when he runs a trail of fire is left behind him. He can move his molecules so fast he can vibrate through solid objects.