Donald Rabin carefully placed his flute made of silver and 18-karat gold next to him on a Chicago train.
“Do not forget it, Donald, do not forget it,” he remembered thinking as he struggled with other belongings, including a suitcase and laptop, on Jan. 29. He had just spent two weeks in St. Louis with his family and stopped in Chicago to visit a friend for the weekend before flying home to Somerville, Mass.
As the blue line train pulled in to the Logan Square stop, Mr. Rabin, 23, a graduate student at the Boston Conservatory at Berklee, gathered his things, rushed out of the car and bounded up the station stairs to catch a ride.
Suddenly, panic seized him.
“Oh my gosh, oh my gosh, oh my gosh,” he recalled thinking. “I don’t have my flute.”
For the next four hours, Mr. Rabin hopped from train to train, still hauling his luggage, as he searched in vain for the instrument, which he said he bought for $22,000. He spent the weekend calling each station stop on the blue line and the Chicago police.
Then he started calling news outlets throughout the city, hoping publicity would help. He posted a plea for help on Facebook, describing the sentimental value of the flute, which he said he bought in 2016 with money he had inherited after his grandmother died from breast cancer.
He refused to lose hope.
“There has got to be some good soul out there who turned it in,” Mr. Rabin recalled thinking. “I’m going to put all my faith in this person.”
It turned out someone had found the flute, but Mr. Rabin would need more than faith to get it back.
On Jan. 30, Gabe Coconate, 42, the owner of West Town Jewelry and Loan, said he was getting ready to close his shop when two men and a woman approached the store and offered to sell him a silver-and-gold flute.
According to Mr. Coconate, one of the men, who identified himself as Lukas Mcentee, 33, said he wanted $7,500 for the instrument and began telling a story of how the flute once belonged to his father who had died.
Mr. Coconate, who has been in the pawnshop business for 20 years, was skeptical.
“I hear my-mom-and-my-dad-dying stories all the time,” he said in an interview on Saturday.
But Mr. Coconate agreed to lend the man $500 and keep the flute for the weekend so he could do research on the instrument and find out its worth. He took the man’s identification card and entered his name and date of birth, along with a photo of the flute, into LeadsOnline, a website that helps track stolen goods.
The next evening, Mr. Coconate was watching the news with his wife when Mr. Rabin’s story flashed across the screen.
Mr. Coconate said his wife asked if that was the same flute he had at his pawnshop.
“Yes, it is,” he replied, then called the Chicago Police Department.
On Feb. 1, Mr. Mcentee, his girlfriend and friend returned to the shop and asked Mr. Coconate to buy the flute or to give it back, telling him he had offers from other shops willing to give him $10,000.
At the advice of the police, Mr. Coconate lied to him and said he had sent the flute off to be appraised to see if it was real gold.
Mr. Mcentee returned the next day, pulled out a wad of cash and said he wanted the flute back.
“I said, ‘Lukas, this has been all over the news,’” Mr. Coconate recalled on Saturday. “‘You’re not in trouble. You did not steal it, but it’s not your flute.’”
“Finders, keepers,” Mr. Mcentee replied, according to Mr. Coconate, who refused to take the cash or return the flute.
That is when Mr. Mcentee grew agitated, Mr. Coconate said.
Mr. Coconate then called the Chicago police, who explained to Mr. Mcentee over the phone that the flute was the subject of an investigation and that he needed to leave the pawnshop.
The Chicago Police Department did not immediately respond to requests for comment. Mr. Mcentee declined to be interviewed.
Mr. Rabin, who flew back to Boston that day, later received text messages from Mr. Mcentee apologizing for trying to pawn the flute. He said he would return the instrument but first Mr. Rabin would have to wire him $550 so he could pay back the loan he had gotten from Mr. Coconate.
Mr. Rabin called the police, who told him not to wire anything. On Wednesday, the police told him they had recovered the flute.
He flew back to Chicago, where officers returned the flute. As a thank you, Mr. Rabin played “Somewhere Over the Rainbow” for 20 officers at the station house. It was the first time he had played for a live, in-person audience since March.
Mr. Rabin said he was so happy he felt like weeping.
“I was in a totally different world,” he said.
He said that he felt terrible that Mr. Coconate was out $500 and has asked people on Facebook to help him raise money for the pawnshop owner.
Mr. Rabin said he was not angry with Mr. Mcentee, who has raised more than $13,000 on a GoFundMe page that says he and his girlfriend “have both been homeless on and off for years.” Mr. Rabin donated $25 to Mr. Mcentee and sent an additional $67 through an instant-payment app.
“I really understand what it was like to not have money,” said Mr. Rabin, who has taken out loans to pay for school and had to borrow money from friends to pay rent. “We’re only humans on this planet. Everyone is bound to make mistakes in this way.”
He and Mr. Coconate talked on Thursday about what happened. Mr. Coconate said Mr. Rabin expressed hope that Mr. Mcentee might repay him the $500 from the money he had raised for himself.
Mr. Coconate said he was not optimistic.