It has been a year and a half since Kristi Goll posted a desperate plea to Facebook asking strangers to get themselves tested and see if they could be an organ donor for her son - and though the situation was dire at the time, the story has a happy ending.

Jackson Arneson, who was 8 years old at the time, was born with a condition called posterior urethral valves, meaning that his kidneys would slowly lose function until they stopped working altogether. In February 2017, he was given a grim prognosis: if he couldn't find a replacement kidney with O positive blood and plenty of matching antigens, then he most likely would not survive the year.

All of Jackson's available family members got tested to see if they were a match, but to no avail. Goll then made a Facebook post asking strangers to get tested, and the message was shared thousands of times.

One month after publishing the post, they still couldn't find a match. Then, it was finally seen by Lindsey Bittorf of the Milton Police Department.

Bittorf, who does not live far from Goll's home in Janesville, Wisconsin, was struck by the mother's emotional plea. After seeing the post, she spent an entire day at the hospital getting psychologically and physically tested to see if she could be a match for Jackson.

"If roles were reversed and it were my kid, I would move hell and earth for my kid, too," Bittorf told CNN.

Despite the odds being pretty low, doctors were surprised to find that Bittorf was an ideal match.

When Bittorf got the test results, she decided to surprise Goll and Jackson with the good news; she had never met the family, and they did not yet know that she was trying to be a donor. She collaborated with Jackson's grandparents to orchestrate the time and place, and then she showed up on the family's doorstep with two wrapped presents containing framed pictures declaring she was Jackson's kidney donor.

Goll was initially surprised to see a police officer standing at her door - but she was even more stunned when she opened the gift and saw what was inside. The emotional mother couldn't help but burst into tears.

"I took an oath to serve and protect my community and now my kidney will serve and protect you," Bittorf told Jackson.

Bittorf and Jackson underwent the four-hour surgery back in June 2017. Though he has been in and out of the hospital over the course of the last year to make sure that the kidney is working and recovering, Jackson is alive and relatively well - and it is all thanks to a woman who used to be a total stranger.

Not only that, they're now best friends.

"I've told her so many times," Goll told WMTV of her gratitude towards Bittorf. "I don't even know how you thank somebody for doing that for you. You know, I mean as something that's so priceless."

(WATCH the 2017 interview below)

Pass On The Positive Story Of Friendship To Your Friends - Photo by Gutzman Photography