While riding the subway in Chicago, the train is derailed, prompting Luke to save the commuters with his powers. He is thanked and taken back to the home of Alexandra Knox. While at an energy research lab, her lover William Robinson accidentally revives the creature Zzzax with his experiment. In doing so the creature absorbs his life force and seeks out Alexandra wanting to change her into an energy being just like it.
Caught in the middle, Luke defends the girl from Zzzax, but ultimately the creature manages to defeat Luke and take the girl back to the lab. Luke tracks the creature and battles it one more time, managing to destroy it when the creature stumbles close to a broken gas main during their fight. The resulting explosion seemingly destroys Zzzax, and Luke and Alexandra manage to escape any harm.

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