Darkman was once Dr. Peyton Westlake, a brilliant chemist. He was trying to invent a synthetic "liquid skin" for use in creating prosthetics for burn victims, but the skin would only last 99 minutes in the light before melting. Peyton's life took a turn for the worse when his girlfriend Julie Hastings discovered that Louis Strack, Jr. was secretly paying off city zoning officials to renovate the "bad" section of town.
Acting on orders from Strack, Robert G. Durant and his gang broke into Peyton's laboratory looking for the Bellasarious Memorandum that proved what Strack was up to. They killed his assistant Yakitito and then tortured Peyton by burning his hands and dunking him into volatile chemicals, then leaving him for dead after rigging the lab to exlode. When the building blew up, a badly-burned Peyton was flung into the nearby river. He barely survived and was found as a John Doe and taken to the hospital, where Dr. Bridget Thorne performed a radical life-saving procedure that severed his pain receptors, giving him augmented strength and increased rage.
Now "Darkman," he escaped from the hospital and tracked down his tormentors. After interrogating and then killing Rick Anderson, Darkman learned the name of Robert G. Durant and then rebuilt his ruined lab, making masks of Durant and his remaining henchmen in order to fool them and sow distrust throughout Strack's organization. He set Pauly Mazzoluca up to be killed by Durant in this fashion. After framing Durant himself for robbing a convenience store, Darkman used a Durant mask to impersonate the henchman leader and steal some of Strack's payoff money from Hung Fat. This plan backfired when the real Durant got out of jail and interrupted Darkman.
Later, Darkman made a mask of his old self as Peyton Westlake in order to try and get back together with Julie, but the 99-minute limit of the liquid skin, combined with his heightened temper, culminated in him attacking a carnival booth worker and fleeing back to his warehouse hideout. Julie followed, and it was through her that Strack learned who Darkman was and sent Durant and the remaining henchmen to eliminate the vigilante scientist, kidnapping Julie in the process. After killing both Smiley and Rudy Guzman, Darkman battled Durant in a helicopter and finally killed him (or so he thought) when he caused the 'copter to crash.
Impersonating Durant once again Darkman joined Strack and a captive Julie atop Strack's partially constructed new skyscraper, but Strack uncovered the imposter when Darkman was mistakenly led into believing that Durant had children when he was actually childless. Initially Strack tried to persuade Darkman to join his side, and when Darkman refused the two battled. Strack was slain when Darkman dropped him off the side of the building. He saved Julie and, his revenge complete, Darkman declared that Peyton Westlake was dead forever and fully embraced his new vigilante persona.
Darkman's further adventures involved the resurrection of Durant. During this time, Darkman/Westlake discovered that another scientist named David Brinkman was also working on liquid skin research and, in the guise of Westlake, approached him and proposed a partnership. Brinkman accepted, but any hopes for continuation in liquid skin research (and a normal life for Westlake) were dashed when the newly rebord Durant's henchmen killed Brinkman when he refused to sell his building, which Durant and Dr. Hathaway needed to build their Vigilante laser weapons. Darkman found himself once again going up against Durant, and, impersonating Durant's henchman Eddie, sat in on a meeting at Durant's headquarters wherein he learned that the building now belonged to Dr. Brinkman's sister, Laurie, from whom Durant intended to buy the building.
Darkman, as Westlake, warned Laurie that the men she was selling her brother's building to had murdered him, causing her to turn down Durant's offer. Afterwards, she was abducted by Durant's men and taken to the Brinkman building and held prisoner. In order to rescue her (and kill Durant once and for all), Darkman wore a mask of Durant's henchman Ivan after learning that modifications were being made to Durant's limousine to make it armored. Darkman knocked Ivan out and drove the limo back to the Brinkman building, and attempted to kill Durant by giving him poisoned pills, but Durant suspected something was amiss because Eddie always carried his pills, not Ivan. Durant's suspicions were confirmed whent he real Ivan returned, and Darkman was exposed.
A fight followed during which Eddie and Ivan were slain, and Durant took Laurie hostage in an attempt to escape in his limo, only to discover that Darkman had made "modifications" of his own to the car: namely, installing a remote control system that allowed him control of the car. He freed Laurie and then locked the doors of the limo, and killed Durant for good by setting off a bomb he'd planted in the car. Having saved his friend's sister and gotten rid of his old enemy once and for all, Darkman began to devote his life to his research once more, funding it by stealing money from various criminals, especially drug dealers like Peter Rooker. One day Darkman was approached by Bridget Thorne, one of the doctors who had worked on him while he was in the hospital before.
Thorne offered to give him the ability to feel again, and to provide him with a more advanced laboratory, funded by her wealthy father, for him to continue and hopefully perfect his liquid skin research. Although initially skeptical, Darkman ultimately agreed, only to be betrayed by Thorne who was actually working for Peter Rooker, who confiscated both Darkman's perfected liquid skin and the computer disk containing his research notes.
Placed under Rooker and Thorne's control via an implant in his neck that gave them the ability to administer pain directly into his brain, Darkman was imprisoned and forced to become Thorne's test subject for her experiments in hormones and steroids. As it turned out, the surgical procedure Thorne had performed on Peyton Westlake had increased his strength and rage chemically; Thorne harvested from Darkman these chemicals, which were then given to Rooker's henchmen in order to make them super strong and super mad, and totally unstoppable.
Escaping and removing the implant in his head, Darkman sought to learn precisely what it was Rooker was up to, and thus made a mask of Rooker and impersonated him whenever he wasn't around. He learned Rooker was in fact a man with a family. A wife, Angela, and a daughter, Jenny. This made Westlake yearn for the kind of life Strack and Durant had denied him years before. As he grew attached to Angela and Jenny he also learned that Rooker planned to send his superpowered henchmen to murder district attorney Ryan Mitchell. Darkman was able to stop the murder attempt and get two of Rooker's super-strong thugs killed by Mitchell's security, and then Rooker, taking the super-chemical himself, retreated to an abandoned warehouse with his remaining minions, with his own wife and daughter as hostages.
Darkman killed Rooker's remaining men, and then fought the super-powered Rooker himself. During the fight, Darkman's disk of notes was destroyed but he managed to reclaim from Rooker the tube containing his only sample of perfected liquid skin. As Rooker attempted to run Darkman over with a skiploader, he ruptured a gas maine, which burned Jenny in the face. After Darkman killed Rooker by dropping him into a crushing machine of some sort, he grabbed Angela and the injured Jenny and escaped before the warehouse exploded from the gas leak. The burned Jenny was whisked to a hospital, and Darkman found himself faced with a choice. Either he could use the liquid skin for himself and return to a normal life as Peyton Westlake, or he could give it to Jenny instead.
He chose the latter, and returned to his life as Darkman forever.