For the next edition of The Curious Case Of... Investigation Discovery's new docuseries will be shedding light on the ultimate alleged conman, and TV insider has a chilling new sneak peek of the episode, "Orphan Imposter," embedded above.

In this exclusive new preview of Monday night's episode, we learn just how convincing the subject of the segment, "Nicholas Rossi," was to even those closest to him.

"We go to Flemons in Providence. He's got a nice suit on. He's cleaned up. He's got a beautiful wife named Katherine. Let me tell you that girl, his wife Katherine, pure as snow," an interviewee recalls of his encounter with Nick.. "He's bragging how great he's doing, and I mean he talked like he was a Wall Street kid, like he was making tons of money. And we're drinking bottles of wine, having steak, appetizers, shrimp cocktail -- we were there about four hours. The bill had to have been about $1,200. At the end, I gave Nick a hug, I embraced him, I said, 'I'm very proud of you. Let's keep in touch.' It was great."

As good of an impression as the night left him with, though, he soon learned the ugly truth behind that showing of success.

"Two months after that, I get a phone call from Katherine," the story continued. "She says, 'Nick's not the person you think he is. He's robbed all my money. He burnt out my credit. A family member of mine, he stole their identity.' I said, 'Really? But he paid for dinner.' She said, 'That was my credit card.'"

That wasn't even the worst thing his wife had to say about him, either. She also accused him of systematically torturing and sexually assaulting her while convincing her family he was a good person.

Check out the full clip above for the harrowing details (but do be warned, they are quite disturbing).

Nicholas, whose real name was Nicholas Alahverdian, allegedly faked his death in 2020 to escape sexual assault charges in Utah and escaped to Scotland. After receiving treatment for Covid-19 in the hospital, though, he was identified. Nick then claimed he was an orphan named Arthur Knight and that he was being framed. He was extradited to face charges in Utah in 2024.

The logline for the episode is: "Master conman Nicholas Rossi fakes his death to evade justice, adopts new identities, and leaves a trail of alleged crimes across continents. Now resurfaced as 'Arthur Knight,' he spins his most audacious con in court."

Still ahead for this season on Curious Case Of... are "The Funeral Home of Horrors" about a couple who stored bodies instead of cremating them, "The Doomsday Cat Cult" about, well, exactly that, and "Jodi Hildebrandt" about the title woman and her infamous partner Ruby Franke who were convicted of child abuse for their extreme parenting methods.

The Curious Case Of.., Mondays, 10/9c, ID