The Peruvian version of the international television game show franchise The Moment of Truth arrived in Lima in mid-2012. By that time, the program had been produced in dozens of countries around the world, including the United States, where it aired on Fox in 2008 and 2009. In Peru, the show was called El Valor de la Verdad ("the value of the truth"), and the format was essentially the same as it had been everywhere else: A contestant is brought into the station and asked a set of questions, some banal, some uncomfortable, some bordering on cruel, all while hooked to a polygraph.

The answers are cataloged. Then, a few days later, the contestant is brought back to go through the questions once more, this time before a studio audience. The answers given are compared to the results of the polygraph, and for each truthful response, the contestant wins money. If she lies — or rather, if the polygraph says she lies — she loses it all. Naturally, the more money at stake, the more compromising the questions become. The contestant has the option of calling it off after each answer.

In Peru, the show's host was Beto Ortiz, who in a recent national poll was named the country's most powerful TV journalist. A balding, heavyset man in his mid-40s, Beto has long been one of the more successful and controversial figures in Peru. He is sharp, inquisitive, funny, and has gained millions of fans; the television critic Fernando Vivas, who writes for El Comercio, Peru's most influential newspaper, described Beto as "a monster on the scene, with all the ambivalence implied by the word 'monster.'"

When Beto first made the transition from print to television, he was known for his deeply reported stories about the seedier aspects of urban life: street kids, punks, prostitutes. He was unlike anyone else on the air. Today, in Lima, you need only say "Beto," and everyone knows whom you're talking about. When asked what it was like being famous, Beto responded: "That's like asking me what it's like being fat. I don't remember what it was like being skinny."

The show's first contestant was a young woman named Ruth Thalía Sayas Sánchez. She was 19 years old, with shoulder-length brown hair and an easy smile. She and her siblings were born in the province of Huancavelica, hundreds of miles from Lima, but had been raised on the outskirts of the capital in a working-class area called Huachipa. Not long ago, this area was a provincial escape from Lima's humid, miserable winters, but by the time the Sayas Sánchez family moved in, the neighborhood was in the midst of an unseemly transition, away from its agricultural past and toward its frenetic, urban future. And so both ways of life coexisted, sometimes uneasily: Young men tended to mototaxis; slightly older men grazed horses. Stray dogs lapped water from dirty puddles in the middle of rutted, unpaved roads, and large plots of farmland sat amid half-built houses, rebar poking out of the concrete, piles of bricks lying in the street.

This was where Ruth Thalía grew up, though she would admit to Beto that she longed for something better. For his part, Beto was, at least initially, unimpressed with Ruth Thalía: "Average," he said, when asked to describe his first contestant. "Pretty, but nothing special." When the cameras began to roll, however, something changed. Ruth Thalía brightened, carrying herself with the confidence of a young striver, comfortable under the lights, even playful. "She liked being on television," her sister, Eva, would say later.

According to the rules of the program, every contestant could bring three guests. Ruth Thalía was accompanied by her parents, Leoncio and Vilma. Leoncio seemed worried from the outset. "I'm afraid of what I might learn about my daughter," he told Beto when he was introduced on camera. Vilma was more optimistic. She was a small woman, with a wide smile and glowing light-brown skin. Ruth Thalía's parents had an Andean pop band, Vilma Sánchez y los Chupachichis del Perú, that often performed in the dustier sections of the capital. Vilma sang, and Leoncio played the harp. As far as Vilma knew — as far as her daughter had told her — Beto would be asking about her arrival in Lima; about how the family had survived those first years in the capital, selling watermelon and pineapple in the market; about those days when the girls still spoke only Quechua, one of Peru's indigenous languages, and were bullied at school for it. These were satisfying memories for Vilma. They'd worked hard, through difficult circumstances, and though they would never have a lot of money, their two daughters were studying at a local university. It's the typical, heroic story of Lima's hundreds of thousands of migrants, no less admirable for being common. "I was happy to go," Vilma said later. "I was going to say, 'I'm from Huancavelica and proud of it, Mr. Beto!'"

Ruth Thalía's third guest was a handsome, timid young man named Bryan Romero Leiva. He wore his brown hair short and combed forward slightly. He was 20 years old, drove a mototaxi, and had been raised on a steeply sloping dirt road near Ruth Thalía's home. He had soccer posters adorning the walls of his old room just off the dirt-floor kitchen, and he kept a cat and a rabbit as pets, both black, as was his preference. He wasn't a dour or unpleasant boy, though; in fact, Bryan's mother, Mery, described her son as helpful and kind. And he hadn't had it easy, that was for sure. He'd stuttered, Mery said, ever since an old boyfriend of hers had pushed him down the stairs when the child was only 8. For years, Bryan had accompanied her to the market at dawn, helping her sell breakfast plates to the workers. At the time of the taping, he was renting a room in the neighborhood, just a few minutes' walk from his mother's house.

"I don't know why," said Vilma, "but I hated that kid."

On the show, in front of the cameras, Bryan was tense, his right leg shaking anxiously.

"You seem nervous," Beto said. "What are you so nervous about?"

"That she may have cheated on me."

Everyone laughed, including Ruth Thalía.

Beto paused. "Let's not forget this is just a game," he said.

The show's opening questions were light: Have you ever skipped school without your mother's knowledge? If you found 1,000 soles, would you return them? Ruth Thalía's parents joked along with Beto, as their daughter copped to these minor moral failings. There was more, of course. David Novoa, who was a producer with the show at the time, later admitted he felt bad. He'd done the initial interview with Ruth Thalía, had helped Beto formulate the questions that would be part of the show. He'd visited the Sayas Sánchez family in Huachipa and knew their story well. The afternoon of the taping, he was in the control booth, whispering into Beto's earpiece. "I knew it was going to be a surprise, and a shameful moment for them."

Which made Ruth Thalía a perfect contestant for El Valor de la Verdad. It all happened in a matter of minutes, a kind of onslaught. Ruth Thalía revealed that she'd had a nose job, that she didn't like her body, that she wished she were white, that she was only with her boyfriend until someone better came along, that she was ashamed of her parents' manners, that she didn't work at a call center, that she danced at a nightclub. The result was undeniably riveting: this young, reckless woman sharing secrets with an entire country.

Reality television was relatively new on Peruvian airwaves. Peru's economic growth in recent years had led to growing advertisement dollars for local television stations and growing budgets for bigger and more ambitious productions. For the region, however, Peru was still catching up. Formats like Big Brother, which had exploded across Latin America, skipped Peru for years. Importing an international format like El Valor de la Verdad would have been unthinkable until quite recently, and audiences were understandably drawn to shows like these. While Ruth Thalía answered Beto's questions, her parents and boyfriend sat onstage. Over the course of the hour, they crumbled. Vilma all but begged her daughter to stop. Bryan was too stunned to offer much resistance, never stringing together more than a couple of sentences. At one point, he admitted he loved Ruth Thalía. "I don't want to hear more," he said.

She went on anyway. Beto asked Ruth Thalía if she thought Bryan was handsome.

"Uh … yes," she said, hedging a bit.

"And is he smart?"

She laughed. "More or less."

"Does he have a good heart?"

For this response, at least, she didn't vacillate: "Yes," Ruth Thalía said, and the studio audience applauded.

Then came question number 18: Have you ever accepted money for sex?

Vilma bent over, as if in physical pain.

Ruth Thalía answered yes, and the show's announcer, a disembodied, almost robotically precise woman's voice, called out:

"The answer is … true."

There was a long silence.

"Just twice," Ruth Thalía explained. "We needed money. We were in a bad situation. It hasn't happened since, and it won't happen again."

For this truthful admission, Ruth Thalía had won 15,000 soles, or about $5,300 — almost ten months' wages for someone living in Lima. Beto asked if she wanted to go on, in search of 50,000 soles. Before responding, Ruth Thalía said she was sorry for all this. "My mother, my father, my brother and sister are the most beautiful thing in the world to me. I love them with all my heart. Bryan, forgive me for making you go through this."

Then she announced she was done. The audience cheered her decision.

"The truth is always illuminating," Beto said to the cameras. "It will not do harm, even though it hurts."

Ruth Thalía hugged Bryan. His face registered nothing. As the credits rolled, she got down on her knees before her ashen-faced mother and begged for forgiveness.