Alpacas frolic in clover-filled paddocks. Teenagers tend to rescued donkeys and abandoned piglets. Well-fed barn cats laze around on rough-hewed benches. The Rickety Ranch, the New Hampshire Union-Leader wrote in 2014, “is a place where animals and humans go to leave their troubles behind.”

Over the past two years, however, trouble has found its way to the Hollis, N.H., farm. Animals have been savagely killed. Two trucks were torched. The barn was set on fire. Horses’ tails were cut off. Meanwhile, rhyming extortion letters offered to make the violence stop — for the price of $250,000.

The Federal Bureau of Investigation on Tuesday announced a $10,000 reward for tips leading to an arrest in the case, which has so far baffled investigators. According to the FBI, the vandal — or, possibly, multiple vandals — has already committed tens of thousands of dollars’ worth of property damage to the farm. “People have been lucky not to be injured or killed,” FBI agent Brian O’Hara told WBZ-TV.

Surrounded by rustic stone walls and tall pines, Rickety Ranch bills itself as an educational rescue farm run by kids and for kids. The farm’s owners, Diana and Gary Bergeron, take in unwanted, abused or injured animals that would otherwise be euthanized and teach young people to care for them. Many of the children and teenagers who work as volunteers on Rickety Ranch come from tough backgrounds or have disabilities. “Whatever it may be, we accept all with open arms and provide a happy place for them to come and feel secure,” the farm’s website promises.

“We all have a bit of ‘rickety’ in us,” Diana Bergeron told the Union-Leader in 2014. “Some of us have had a troubled past, or are dealing with tough things at school. And sometimes animals, as well as people, can be taught how to trust again.”

Now, that trust has been threatened. Hollis, which is home to multiple family-owned farms selling apples, pumpkins and Christmas trees but has recently been threatened by the slow creep of suburban development, has a mystery on its hands: Who is terrorizing the Bergerons and their animals?

“I saw your flag on your lawn / And time almost gone,” reads one cryptic, typo-riddled letter released by the FBI. Telling the Bergerons that they “will win” if they pay up, the sender instructs them: “I left instructions under glass / On your grass / From here o[n] keep 50k cash on your a–.”

The animal sanctuary has received multiple threatening notes “constructed in a similar way with some rhyme and riddle to them,” O’Hara told WCVB. The FBI hopes that someone will recognize the sender’s distinctive verbiage and be able to identify them.

The extortionist clearly has some knowledge of local affairs: According to the Union-Leader, the town of Hollis is suing the Bergerons over potential zoning code violations involving construction permits. Some of the letters sent to the farm suggest that the sender has the ability to resolve the dispute, the FBI said.

Local officials vehemently deny any involvement. “We are not threatening anybody,” Mark Le Doux, the chairman of the town’s board of selectmen, told the Union-Leader. “Nobody needs this kind of nonsense.”

It’s not the only legal challenge that the farm has faced. In 2014, an inflatable bounce house that had been set up for a fundraising event became airborne in high winds. Two boys inside, aged 2 and 3, were severely injured when it crashed to the ground. Gary Bergeron was later charged with failing to register the bounce house and not having it inspected. He denied that he was at fault but pleaded no contest to the misdemeanor charges and was found guilty, Stateline reported.

The FBI has not indicated that there is any connection between the bounce house incident and the attempted extortion.

The Bergerons have not discussed the threats and property damage publicly, outside of a Facebook post thanking firefighters who responded to their barn fire. On Tuesday, volunteers doing chores on the ranch declined to talk to reporters who had made their way down the slush-covered, potholed road. “The whole thing is just unfortunate, but I think the FBI has a good handle on it,” Gary Bergeron told the Union-Leader. “I don’t want to interfere with what they are doing.”

O’Hara, the FBI agent, told WBZ-TV that the past two years have been a “tough, tough haul” for the couple, who have dealt with relentless harassment. “This family is living in fear,” he said. “They’re constantly watching their back, looking over their shoulder, just wondering when the next shoe is going to drop.”