(CNN) -- What a difference a day makes.
On July 2, Stephanie Headley was counting the days she had left to live. The Ottawa woman is suffering from an autoimmune disease that, without expensive treatment, will cause her heart to fail.
On July 3, thanks to a mysterious stranger who showed up at her door, she had in her hands more than enough money to get the treatment that can save her life.
Two weeks later, she still struggles to explain the dramatic change in her fortune.
"This is a miracle" she told CNN partner CBC, referring to the mystery donor as an "angel that walks among us."
Hope with a cost
For 12 long years, the single mother of four has battled systemic scleroderma. The disease causes her body to overproduce collagen, making her skin, vital organs and blood vessels hard. Eventually the disease would have caused her heart to fail. And Headley says she felt time was running out.
But Headley had hope.
She told the Canadian TV stations, CBC and CTV, that she'd found a doctor in Chicago who could do a stem cell treatment. One with an 80% success rate.
However, the treatment came with a hefty $125,000 (US$ 116,000) price tag -- far out of reach for Headley.
Turning to the Internet
In the age of the Internet, Headley and her family did what many others in similar situations do: they started a fundraising page online.
Money began coming in. And on July 3, a man called the house saying he too wanted to donate.
Looking back, Headley remembers there were unusual things about the phone call. He had a monotone voice, a deliberately altered one. Maybe it was so she wouldn't recognize him, Headley told CBC.
The stranger also said he'd bring a bank draft, which made Headley think his donation could be substantial.
So, she wrote a thank you note and got ready to greet the man.
The stranger at the door
The man turned up wearing reflective sunglasses, a hat and a coat buttoned all the way up. He handed her an envelope without the hint of a smile.
He was "completely stone-faced" she told CBC.
"I handed him the thank you card."
Then as he turned to go, she said, "I said 'God bless you.' Then he smiled a big smile."
He walked off.
Headley went inside not knowing what the envelope contained.
"When I opened it, I thought I was seeing the numbers wrong, the decimals wrong, the zeroes wrong."
The draft was for $128,000 (US$ 119,000)
Headley couldn't believe it.
She collapsed, she cried. She even hyperventilated, she told CBC.
"I said 'Thank you God! Oh my God, I'm going to be saved!'"
Then when she regained her wits and walked outside to seeif she could find her benefactor he was gone. There was no trace of the tall, slender man with the big check.
But if they could find him, Headley told CTV, "I would give him a big hug" and tell him, "You have absolutely saved my family."
Skylar Skinkle, Headley's daughter, summed it up best.
She told CTV: "This is my mom's life on a piece of paper."
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