In what may or may not be a bizarre case of letting a friend crash at your place gone terribly wrong, a New Jersey man is seeking hundreds of thousands of dollars in damages from a former family friend after he allowed her to temporarily stay in his Upper East Side apartment, only for her to allegedly (deep breath) put the place up on Airbnb, take all his stuff, and falsely accuse him of sending her an unknown white powder in the mail.

In a $300,000 lawsuit filed Tuesday in Manhattan Supreme Court, the man, Alec Jain, claims that in August, he offered his $3,800 a month rental in a townhouse on 75th Street just off Fifth Avenue to friend Brianna Hallam, who was apartment-hunting at the time.

According to the suit, Hallam moved into the place in September; soon after, Jain discovered that she had allegedly put the apartment up on Airbnb. This was apparently forbidden under the terms of his lease (also, kind of poor form), which he says he told Hallam. Jain reached out to Airbnb about the listing, only to find himself engaged in a sort of landlord-tenant whack-a-mole, with Hallam allegedly creating one new account after the other to list the place.

Airbnb did not immediately respond to Gothamist's request for comment on Jain's allegations.

Jain says he told Hallam, whom he also apparently had lent money to, that she needed to leave the apartment. Meanwhile, he says, he let his landlord know about the situation.

Things seemed to be going according to plan around November, when Hallam apparently turned over the keys to the place and then moved to Switzerland to live with her boyfriend.

This may have been a rash decision, as according to the suit, the relationship fell apart and Hallam was back in New York before Christmas. She then allegedly but unsuccessfully tried to get the keys back from building management.

Around this time, Jain says, he came back to his place and found that most of his belongings, including jewelry, clothing, and electronics, were no longer there. Apparently unsympathetic to his plight, his landlord soon sent him an eviction notice, claiming he'd breached the terms of his lease and demanding almost $20,000 in penalties.

Jain's suit, first reported in the Daily News, claims that he is still fighting to evict Hallam and that she is still listing the place out on Airbnb. (There seems to be one apartment on Jain’s block being rented out on Airbnb, but it doesn't appear to be in his building.)

Hallam, though, disputes Jain's characterization of events. She told the News that the saga began when Jain agreed to provide her housing as a condition of her employment at Apercu, his financial consultancy, where she was apparently working. (Her LinkedIn lists Apercu as her current employer, though the News says it's no longer in business.) She said that the housing turned out to be Jain's own apartment, which she says Jain, not she, was listing on Airbnb.

"He's never had a key, his stuff has never been here, he's never spent a night here," Hallam told the News.

She accuses Jain of breaking into the place, stealing her stuff, and then leaving the curious calling card of a lily and dirty women's underwear on the bed. The News posted a photo, apparently taken by Hallam, of a bed with a lily and what appears to be underwear (cleanliness unclear) on it.

Meanwhile, Jain says Hallam made a baseless accusation that he sent her some sort of white powder (perhaps ersatz anthrax) causing "emotional distress," and that she had actually thrown out her own stuff to extort money from him.

Jain's and Hallam's attorneys did not respond to Gothamist request for comment, and Hallam herself did not respond to Gothamist's request for comment. Whatever, something tells us we're never going to get to the bottom of this one.