Sisters Ayda Zugay and Vanja Contino fled their war-torn country for the United States more than two decades ago. They sat next to a woman on the airline who did an incredible act of kindness that altered their lives.

The teenage migrants were fleeing their homeland, Yugoslavia, in May 1999. As they were leaving, Ayda, who was 12 at the time, recalls bombs dropping all around them.

The sisters sat next to a woman on the plane who listened to their story. The thoughtful traveler handed them an envelope but requested that they not read it until they were off the plane.

They were surprised to find dangling earrings and $100 inside when they did. Tracy also left a beautiful note for them, which she signed with her first name. For the young refugees, it was a much-needed blessing because they had nothing with them—not even a dollar.

Ayda and Vanja moved in with their brother, an Iowa college student. For an entire summer, they survived on pancake mix and cola thanks to Tracy’s gift. Fast forward 23 years, and that single act of generosity affected the rest of their lives. Ayda is a Boston University graduate who now works in the non-profit sector. Vanja works as an anesthesiologist and is married with two children.

Ayda has been looking for the friendly stranger they met on their flight from Amsterdam to Minneapolis for the past decade. She remembered the woman holding a tennis racquet and talking about playing tennis in Paris.

She had contacted hotels, tour companies, and airlines in the hopes of locating Tracy, as well as posting anonymously on Reddit, speaking with media, and seeking assistance from refugee organizations.

Many of those organizations used Twitter to share a video of Ayda telling her story and requested the public to contact them if they had any clues. Ayda initially noticed a tweet from one of Tracy’s kids, who claimed that the note’s handwriting resembled her mother’s.

Next, Tracy’s tennis coach, Susan Allen, reached out after also recognizing Tracy’s penmanship. More than that, the story just made sense. “Knowing Tracy, that is exactly what Tracy would do,” Susan told CNN.

Susan then reached out to her fellow coach, Deanne Sand Johnson, to scour their records. Their search confirmed that in May 1999, their company, Love / To Travel, gave Minnesota women a chance to travel abroad to play tennis and watch tournaments.

They flew a group of 18 women, including Tracy, to Paris that month to witness the French Open. Deanne kept a scrapbook documenting their trip, including a receipt from a travel agency with the group’s itinerary. It showed that the second leg of their journey was a flight from Amsterdam to

Minneapolis on May 31, 1999—the same date and route that Ayda and Vanja recalled flying. Susan created a group text putting Tracy and Ayda in touch, and the latter suggested a Zoom call the next day. Tracy told the siblings that she clearly remembers what she felt when she met them.

“It just touched my heart so much that I just felt compelled that I had to help you in some way,” she said. Vanja, who now lives in Connecticut, told her: “Your generosity is still in me because I’ve been paying it forward ever since.”

After their Zoom call, the previously nervous Ayda felt stronger. “You know those huge doors that they have in old places across the world? It felt like that big, heavy door just got shut. And I’m finally able to move forward and thrive. … And it just makes me so happy,” she said. “Thank you for reminding me to be strong.”

Tracy said she was the grateful one. Now that their story has gone viral, she hopes that it inspires others to give back. “I just want to encourage everybody in the world to just be kind,” she said. “What does it hurt? Except it helps everyone.

Smile, make eye contact, help anyone that’s in trouble or in danger. And I just don’t know why anyone wouldn’t do that. So, I’m very, very thankful that I have found you girls, that you have found me.” Vanja introduced Tracy to her daughters during the call, while the latter introduced one of her daughters and two of her grandkids.

The trio intends to meet in person someday, including a plan to spend a Memorial Day weekend together, which marks the anniversary of the sisters’ arrival in the United States. Click on the video below for more on this story.