Every now and then, if you are very lucky or unlucky, if you are very innocent or incredibly guilty, and have sat through all the meetings and depositions and requests for summary judgment and pre-trial hearings, you will get a chance to meet your accuser face-to-face in court.

In some versions, they call him Judas. In some, they call him Sammy the Bull. In some, they call him Kid Twist. In the version being lived by Elizabeth Holmes, the disgraced onetime billionaire C.E.O. of the defunct blood-testing start-up Theranos, who is currently on trial for every variety of fraud in a federal courthouse in San Jose, California, his name is Adam Rosendorff, and he is a slightly disheveled scientist-physician who, from 2013 to 2014, oversaw the lab at the company.

It was Rosendorff who battled Holmes about the performance of her all-in-one blood-testing gizmo, the Edison, which, according to Rosendorff, was so inaccurate as to be useless. He said he was being besieged by complaints from doctors.

Adam Rosendorff (left), former lab director at Theranos Inc. Theranos founder Holmes faces up to 20 years in prison if convicted of fraud and conspiracy charges.

“The company,” he told the jury, “was more about P.R. and fundraising than patient care.”

It was Rosendorff who transferred 150 possibly incriminating e-mails—these could show what was really going on at Theranos—from his work e-mail to his personal e-mail before he quit. It was Rosendorff who spilled the beans on the device—it’s all bullshit!—first to a few lawyers (“I felt obligated from a moral and ethical perspective to alert the public”), then to The Wall Street Journal’s John Carreyrou. He used Rosendorff’s account to write the inaugural muckraking article—Carreyrou acknowledges Rosendorff as his “first and most important source”—that set off the chain of events that turtled the company and landed Holmes in this nightmare.

And now this businesswoman who once hosted Joe Biden and bestrode Silicon Valley like a colossus is forced to sit on a hard, wood chair as prosecutors pick through her most intimate exchanges. Like the text in which she calls her business and love partner, Sunny Balwani, “My King.” Or the text in which she calls him “Tiger.” No wonder Holmes enters court each day hanging onto her mother’s hand, tethered to it like a hot-air balloon. If she were to let go, the shame of the moment would carry her away.

“I felt obligated from a moral and ethical perspective to alert the public.”

Rosendorff has not been the most glamorous witness to appear for the prosecution—that would probably be “Mad Dog” Mattis, who invested in Holmes’s company and sat on her board. But he’s been the most important. Rosendorff ran the lab, which means he is able to take the jury into the nitty-gritty of the engine room, to show them how the dingus worked, or, in this case, did not work. He spent five-plus days on the stand—that is, most of the fourth and fifth week of the trial, facing friendly examination and testy cross-examination. This was a witness who would make, or unmake, the case—that’s the sense you had. Which is why the defense used every method to impeach the testimony of the man in the sloppy blue suit.

Rosendorff, though, actually does have a kind of glamour. That he came to the case not by request or subpoena but as a whistleblower encapsulates the moment. The woman who leaked the Facebook documents. The four-star general who called the Chinese general and said, Hey, ignore that lunatic, we’re not going to nuke you.

This is the age of the whistleblower, a figure that will take a place in the national pantheon beside the trapper, the cowboy, and the astronaut—a hero and symbol of our time. (I don’t know about your kids, but mine plan to dress as whistleblowers for Halloween.) The system is so rank that the whistleblower amounts to the only hope we have left—that an insider will repent, ask for protection, and sing. In good times, the whistleblower is a rat. But in bad times, the rat is a hero.

Lance Wade, attorney for Elizabeth Holmes, arrives at federal court in San Jose.

Defense attorney Lance Wade seemed to suggest that Rosendorff, as the adult in the Theranos lab, the man with the fancy education (Holmes dropped out of Stanford after two semesters) was actually the one at fault for any fraud or malfeasance. This came out in cross-examination but gives you a pretty good sense of what the defense will be.

Holmes pitched herself to would-be investors and health-care executives as a strong person, a leader, and a trailblazer, the second coming of Steve Jobs and the first female start-up billionaire. She is now being recast from Ayn Randian hero to victim of the patriarchy, set up by Adam Rosendorff, manipulated and emotionally abused by her tiger and king, Sunny Balwani, who worked Holmes like a puppet and left her to take the blame. If she made a mistake, it was only in believing Sunny. If she lied, it was only because Sunny told her what to say.

They met on a trip to China when she was just 18, a naïve young woman. He was 37 years old, a powerful man who got her to move in with him, then took her over. The power he had over her, his influence and his lies—that’s what has led her to this courtroom.

Former Theranos president and C.O.O. Ramesh “Sunny” Balwani.

In refuting this, the prosecution, in its discovery, has seized and released dozens of texts that passed between Holmes and Bulwani from 2013 to 2015, the years in which the profile of the company peaked—Theranos was worth $9 billion in 2014—and crashed. Theranos is currently worth nothing. According to Assistant U.S. Attorney Robert Leach, these texts show Holmes and Bulwani “controlled Theranos as equals and made significant decisions in consultation with each other as partners do.”

In the texts, Holmes actually seems more gung-ho than Bulwani, who tries, like Roxanne, to put on the red light. He warned Holmes, saying, “We need FDA clearance,” in April 2015. He advised Holmes to cut down on her media appearances, as Theranos still lacks “solid substance.” He told her to stop telling everyone that the Edison performs 200 tests with a single prick of blood.

But it’s less the corporate than the personal content of the messages that sticks with you. Reading them you get the sense that, above all else, Theranos was a love story. Sunny and Elizabeth, twisted and criminal and strange, but also a perfect romance for right now. It was Bonnie and Clyde during the Depression, Julius and Ethel in the Cold War. This is who we get now: Elizabeth and Sunny.

A secret office fling—no one on the board and few people in the company knew about the relationship. Cutting-edge technology. The promise of a billion-dollar I.P.O. Power Imbalance. Questionable Science. Black Turtlenecks and the Lou Rawls–like baritone of the C.E.O.’s voice. Ambition. Money. Surveillance. She thinks she’s talking in private, but we can hear everything. Theranos: The Love Story. It was a fiery passion as the value climbed. It cooled to an ember when the prosecutors arrived. You wake up from the spree and ask yourself, “What the hell just happened?”

Rich Cohen is a Writer at Large for Air Mail