Rob and Mindy Seay had been told that their baby, Lincoln, had about six weeks to live.
He had just undergone cardiac arrest, and doctors at Seattle Children's expanded his catheter. The hope: That Lincoln would receive a heart transplant before it was too late.
Six weeks came and went.
Those days "were the toughest," Rob Seay said in an interview. "His color became purple. ... That's when true despair started to set in."
"We both knew it: He was out of time," Mindy Seay said. "He was declining to the point where he wouldn't wake up for very long."
Then, on Feb. 18, three days after the six-week estimate passed, the couple from Alaska was told that a donor match had been found.
Seven-month-old Lincoln would receive a new heart.
"He was right on the edge," Michael McMullan, Seattle Children's surgical director of heart transplantation, told the Seattle Times.
"We have a list of patients and he was the one we were most concerned about."
In 2015, 241 babies under the age of 1 received a heart transplant, according to the Organ Procurement and Transplantation Network. Currently, 45 babies younger than 1 are on the waiting list for a heart.
It's been a long journey for the family. When Mindy Seay was about 20 weeks pregnant, she and her husband discovered that their baby suffered from heterotaxy syndrome, a condition that would cause his heart and other organs to develop on opposite sides of his body.
Despite the diagnosis, the couple was happy. After two miscarriages, they were going to have a baby boy.
"When I found out, it wasn't that big of a deal to me," Mindy Seay said. She recalled thinking: "Okay, he's going to need some special care? I'm game. We can handle that."
"We've both been around special needs kids for a long time," she said. "It wasn't terrifying to me."
Lincoln was born on July 14. Twelve hours later, he had his first open-heart surgery, in which doctors placed a shunt in an artery. He was "acting like a healthy baby" after that, Mindy Seay said; but in October, he "went into heart failure."
Lincoln was transferred from a hospital in Portland to Seattle Children's.
The couple's initial plan was for their infant to undergo a series of open-heart surgeries over a span of five years -- difficult for anyone, but especially for such a young child.
Soon, they learned that Lincoln's heart couldn't keep him alive.
"We had no idea that a heart transplant was even possible," Rob Seay said.
"My first reaction was, 'You guys do those? That actually happens?'"
Lincoln was placed on the donor list. Aside from a shortage of donor organs in general, it's especially difficult to find a heart for an infant, McMullan, the surgical director, told the Seattle Times.
"Because of his size, it had to be a young child," McMullan said.
Time was working against them.
"He's been pretty sick and getting sicker," McMullan told ABC News.
"I think he was about to die on us."
But, McMullan said: "Right before he fell off the edge, a heart became available."
Mindy Seay was tending to Lincoln when she was told a donor had been found. She called her husband to break the news. "I couldn't speak; I was in complete shock," he recalled.
"I was trying to talk, and the words weren't coming. I was crying -- the tears were talking for me."
More than a week after his surgery, Lincoln is progressing well. His purple skin quickly returned to normal. He may be moved out of the Intensive Care Unit within weeks, but the family - which includes three other children -- will have to remain in Seattle for a few months before heading back home to Alaska.
Rob Seay hopes other families will learn about organ donation and take it under consideration, particularly before they are in the middle of a crisis.
The couple doesn't know who donated the heart to Lincoln. But well before receiving news that Lincoln had a match, Mindy Seay wrote "an open letter to the mother of the child who will save my son's life," expressing deep sorrow for the loss of another child and deep gratitude for saving Lincoln's life.
"You and I may never meet, may never speak, may never cross paths, but we will be connected on a divine, spiritual level," she wrote.
In an interview Tuesday, she reflected further on that open letter.
"For somebody to be able to, for a family to be able to donate their child's organ during that time is the most selfless and brave thing I can even imagine," Seay said.
"Thank you isn't even enough."