Julie Hastings was the girlfriend of Dr. Peyton Westlake as well as the attorney of Louis Strack, Jr. She discovered the Bellasarious Memorandum which proved that Strack was paying off members of the city zoning commission to let him being construction of the City of the Future along the waterfront. She left the memo at Peyton's lab for safekeeping when she went to confront Strack on the matter, and Strack warned her that his rival Robert G. Durant might try to steal it. She returned to the lab too late: Durant and his gang had rigged it to explode, and Julie thought that both Peyton and the memorandum were destroyed in the fire, telling Strack as much when he pressed the issue at a company party.
Julie began seeing Strack, but then Peyton reappeared, apparently having been in a coma since the explosion. She had no idea that he'd been scarred beyond recognition and was using his experimental liquid skin to look normal again, having become the vigilante Darkman. But because the liquid skin only lasted 99 minutes in direct sunlight, Julie and Peyton could only spend brief periods of time together, with Peyton lying and saying he had physical therapy at a hospital. During a trip to a local carnival where Peyton lost his temper and attacked a carnival booth attendant who refused to give him the stuffed pink elephant he had won for Julie, Peyton's liquid skin began to melt and he ran away.
Julie followed Peyton back to the abandoned warehouse where he had set up his new lab, and discovered his secret. She went immediately to see Strack, hoping he could help her convince Peyton to seek help, only to discover the Bellasarious Memorandum in his office, which meant that Strack was the one behind the destruction of Peyton's lab and Robert G. Durant was his ally, not his rival. Durant's gang followed Julie back to the warehouse and kidnapped her, bringing her back to the City of the Future construction site following an unsuccessful attempt by Durant to kill Peyton/Darkman.
She was held hostage by Strack and one of his men atop one of the partially completed skyscrapers, and during Darkman's ensuing struggle with Strack Julie helped out as much as she could, pushing Strack's goon nearly to his death when he began shooting at Peyton. The goon retaliated by shoving Julie completely off the building, and she was only saved when the ropes used to bind her wrists got caught on a metal rod. She slipped shortly thereafter, but Darkman swung down on a cable and rescued her as she fell before finally killing Strack.
During the elevator ride back down from the building, Julie told Peyton she wanted their old life back, but Peyton said that his ordeal had changed him both inside and outside. He was Darkman now, and Peyton was gone. Julie was left alone when her former boyfriend ran away and disappeared into a crowd as soon as they got back down to street level.