The following days were understandably tense. “It was obvious that he was a suicide risk,” Morales tells NEWSWEEK. “We put him on a 24-hour watch, I mean not even letting him walk alone across the street for a cup of coffee.” Friends of the couple rotated through the apartment, offering food and distraction until Blake appeared to turn a corner. He started sketching again and made plans to drive to Theresa’s funeral in Michigan. On July 17, the day before he was supposed to leave, Blake boarded an A subway train bound for Brooklyn, where he was scheduled to meet a friend, but he blew past his stop and got off the train along Rockaway Beach. As the sun set, he walked toward the water, took off his clothes, piled them neatly on the sand and waded into the brownish Atlantic. Five days later, a fisherman discovered his body off the coast of New Jersey. Near the spot where he’d entered the ocean, authorities found a Jeremy Blake business card with a short note. It didn’t say much, just that he couldn’t live without Theresa.

Jeremy Blake and Theresa Duncan seemed like the perfect couple: beautiful, talented, successful and deeply in love. But beneath the idyllic surface is a darkly modern tale of obsession and paranoia fueled by instruments of a digital age. Duncan and Blake built their lives around computers and the Internet, using them to create innovative art, prize-winning video­games and visionary stories. But as time progressed, the very technologies that had infused their work and elevated their lives became tools to reinforce destructive delusions and weapons to lash out at a world they thought was closing in on them. By the end of their lives, this formerly outgoing and affable couple had turned cold toward outsiders. They addressed friends and colleagues from behind electronic walls of accusatory e-mails and confrontational blog posts, and their storybook devotion to each other slowly warped into a shared madness—what is known as a folie à deux. “This wasn’t who they wanted to be,” says Katie Brennan, a Los Angeles gallery owner and long­time friend. She compares the couple’s late-life delusions to “a kind of terminal cancer” that overtook the true Jeremy and Theresa.

For some, technology and mental illness have long been thought to exist in a kind of dark symbiosis. Blake and Duncan’s case follows a long history that began when the electric age upended daily life with baffling, complex innovations. The first victim is believed to have been James Tilley Matthews, an 18th-century British merchant who thought France planned to take over England with a mind-controlling magnetic machine using technology developed by Frank Mesmer—from whom the word “mesmerized” is derived. More recently, the introduction of television inflamed the minds of patients who believed that their TVs were watching them or broadcasting secrets about their lives. In this regard, the Web is especially powerful. “The condition of being super-social and super-isolated at the same time is an Internet-era kind of thing,” says Fred Turner, a media historian at Stanford University, who speculates that as Blake and Duncan withdrew from friends, “their only reality check left was the wisps of information on their computer screens. And unfortunately, that isn’t a very powerful check.”

Blake was cool and lanky with a shy, brooding demeanor. Duncan was bracingly smart, bright-skinned and blond, with so much energy it often seemed as if she were fueled by some inner reactor. They met in 1995, when he was fresh out of art school and she was a precocious grande dame of Washington, D.C.’s computer-gaming scene. That same year, Entertainment Weekly named one of her fantastical video­games for girls, Chop Suey, the “CD-ROM of the year.” The two fell in love a few years later while working together at the New York digital-media firm IconNicholson, where they teamed up for an acclaimed series of narrative videogames. She wrote the stories; he did the artwork. Raymond Doherty, a longtime friend of Duncan’s, tells NEWSWEEK that he once asked her why the couple didn’t get married. She just laughed. “What more could I want than this?” she said.

That sense of transcendent romance—somehow too big for such a worldly concept as marriage—struck nearly everyone who met the couple. “They would stand almost physically on each other at parties. Not in a weird way, but sweetly, with her hand swung over his shoulder or his hand looping her waist,” says Brennan. “They always seemed to be touching.” Sometimes they seemed a bit too close. “You’d e-mail him and she’d answer, or you’d call her and he’d suddenly be on the phone,” says Brad Schlei, a friend and executive at Muse Productions, a film company in Los Angeles. “It was definitely that kind of relationship.” At the time, though, no one saw cause for alarm, and in 2000 the couple had a critical success with “The History of Glamour,” a witty animated short film about the emptiness of pop stardom that the Whitney Museum of American Art included in its 2000 Biennial.

In 2002, Blake’s career began to blossom. Fascinated with the boundaries between painting, photography and computer art, he pioneered a genre that he called “moving paintings,” a series of digital animations played on plasma-screen televisions. One curator dubbed it “painting with pixels.” Not long after, the singer-songwriter Beck asked Blake to design the cover art and a music video for the musician’s album “Sea Change.” That same year, filmmaker Paul Thomas Anderson hired him to create a hallucinogenic dream sequence for “Punch-Drunk Love,” starring Adam Sandler.

But as Blake’s celebrity and creative confidence grew, Duncan’s professional luck withered. The CD-ROM market tanked, and she struggled to get projects off the ground in other media. Hoped-for ventures with the Oxygen Network, MTV, Para­mount Pictures, Fox Searchlight Pictures and the publishing house HarperCollins all fizzled. Frustrated and bewildered, she began to suspect that the Church of Scientology was deliberately thwarting her progress. In a disjointed 2006 e-mail to an art-world friend, Duncan claimed that Beck, a second-generation Scientologist, had told her about his plans to leave the church. This knowledge, she wrote, would make her “priority No. 1 for their paranoid and dangerous security wing.” (A spokes-person for Beck denied to NEWSWEEK that the exchange ever occurred, and a spokeswoman for the Church of Scientology called Duncan’s allegations “absurd.”)

Thwarted elsewhere, Duncan turned to the Internet, launching a blog called The Wit of the Staircase that cataloged far-flung interests such as cinema, perfume and the history of electricity. But the blog also served as a base for Duncan to mount a case against Scientologists and others who she believed had a vendetta against her. In May 2007, she posted a sprawling entry that claimed a host of people—including Hollywood executives, Republican media owners, the CIA, the FBI and the Department of Homeland Security—were conducting a “smear campaign” against the couple. Duncan’s assault reads like a multimedia performance piece, with hyperlinks and pictures incorporating information from the dregs of the Internet.

Ever supportive, Blake defended Duncan, no matter how outrageous her claims. More than a soulmate, he said that the two shared a “creed”: a lifelong pledge of love and protection. In e-mails to friends, he railed against an organized campaign to stall Duncan’s career. At one point in 2006, he accused Schlei’s girlfriend of being part of the conspiracy. “She has an unfortunate interest in smearing Theresa because her masters told her to,” Blake wrote to Schlei in an e-mail obtained by NEWSWEEK. “Seriously?” Schlei replied. “You’ve got to know that this sounds absolutely insane my friend.” But Blake was unbowed. “If you want me to get a lawyer and sue her for defaming Theresa,” he wrote, “that will be fun.”

This past February Blake took a consulting job at Rockstar videogames, and Duncan searched for traction on a new project. The night before she killed herself, they met with “Scream” producer Cary Woods to outline a noir film—a dream project for some, but it was perhaps too much for Duncan. Her friends speculate that she chose to end her life rather than risk losing another film to forces outside her control. Theresa herself wrote in an e-mail, “The CoS is going to have to kill us before we will give up ANY of our free will or any of our constitutional rights to do and say what we please.” Instead, Blake’s final work, “Sodium Fox,” is an abstract short film that he called a “self-portrait by proxy.” It ends with the image of a ghostly smear of color over the ocean. There are waves crashing on the beach, but the only sound is a crackling radio voice from some mysterious signal, then an eerily prophetic voice-over: “This will take four or five years to describe.” Perhaps, though as a self-portrait of a quietly tragic end, its meaning seems all too clear.