"Find me," she said, before slipping away into the dawn of New Year's Day.
"Yeah, I'll find you," he said, before realising all he had to go on was her first name, Katie, and the fact she was from "DC" - presumably Washington.
Reese McKee, 25, is hoping the magic of Christmas and the power of social media will reunite him with the mystery woman he met in Hong Kong last New Year's Eve.
The Wellington man said he was in Hong Kong when he ran into Katie after they both became lost earlier in the night.
"I was just walking around and admiring the lights and found this girl just crying on the side of the road.
"I went and tried to help her out. She was lost. She'd lost all her friends.
"I just cheered her up. I sort of have this undeniably bad sense of humour that no one can resist laughing at."
They went out drinking later and eventually reunited with her friends before parting ways at 6am, he said.
Although he never got a contact number or email address, Katie's final words, "find me", stuck with him.
After meeting Katie, Mr McKee said he spent weeks searching for her. "But it was pretty fruitless because I had nothing to go on.
"I got the idea to use Facebook in June but the timing wasn't right. I think this time of year people have hope for the magic (of Christmas). If nothing else, it would just be great to get in touch with her and say 'thank you'. To say 'Hi, how are you doing?'."
He hoped a Facebook campaign he started this week would improve his chances.
"The amount of positive feedback and comments that are flowing, it's boggling." The page had been shared with more than 4,000 people.
Aside from her first name, the only identifying details he had of Katie was a photo of her he found on his phone the next morning.
Mr McKee conceded he is "a bit of a realist" and wouldn't be surprised if Katie was seeing someone else. However, he was "foolishly optimistic".
"The chances are billions to one, but I like those odds.
"Even if I could just find her and say thanks, because it's been a life-changing year and it all started that night, really."