Penny Callaghan will never be able to thank the hundreds of volunteers who helped search for her son – but she's determined to try.
The mother-of-two faced every parent's nightmare when eldest son William, who is non-verbal and autistic, went missing on a bushwalk at Mount Disappointment on June 8, 2020.
A year later, Penny, 48, reunited with crew members from the Whittlesea SES, who had scoured bushland to find her boy.
"It was emotional," Penny tells Woman's Day.
"For the team, these searches don't often end well, and it was so good for all of us to meet again and share in that really good outcome.
"I wanted to give back to them. For the effort, the amazing show of support and the positive strength they showed me – how can I possibly say thank you enough?"
William, now 15, and his brother Robin, 13, had been visiting their father when William wandered ahead into the dense Victorian bush.
For two days and nights, more than 500 police and volunteers combed through the scrub for him.
"The turnout was amazing... it buoyed my spirit, and gave me the courage to keep going," says Penny.
"People genuinely felt for Will and wanted to be there looking.
"All the volunteers helped me – offering blankets and food. I would have been really lost without them."
She remembers being so desperate to join the hunt, she was ready to run into bushland but the authorities advised against it.
"Because the bush was really dense they said, 'We can't have two of you going missing,'" explains Penny, who couldn't stop thinking of her son stuck in the freezing conditions as temperatures plunged to around zero degrees Celsius.
"The first night was excruciatingly awful, everything just seemed to go really slowly... I was frustrated and annoyed that I couldn't do more."
Search teams worked hard to adapt their methods to find William, who they knew would find it impossible to call out for help.
Careful to avoid making loud noises that could cause him to be frightened and hide, rescuers sang as they searched instead of shouting his name, and played his favourite song, the Thomas The Tank Engine theme, to coax him from the bush.
On the third day of searching, Penny received word from her partner Nathan, 44, that William had been found alive 1.5km from the search command area.
It's a moment she will never forget.
"I didn't want to picture any worst-case scenarios... so when they said he was alive I just was over the moon," Penny recalls.
Finally, mum and son were reunited.
"Holding Will in my arms... it was beautiful," says Penny, her voice heavy with emotion.
After a night in Melbourne's Royal Children's Hospital, where doctors X-rayed William's foot to check for breaks and removed dirt from his ears, the teenager returned home to begin his road to recovery.
"His feet were swollen for weeks. I could see he'd lost weight," says Penny. "I could see he'd been struggling."
But it wasn't just the physical injuries that needed time to heal.
"Going through that ordeal for anyone is awful, but particularly for someone who gets very confused by the world," she explains.
"But William's such a strong little man, I'm so proud of him."
Reuniting with the Whittlesea SES crew a year after their ordeal, Penny was especially excited to thank unit controller Gary Doorbar who, together with his team, helped execute the search for William.
"Seeing Gary again was lovely and very emotional," she says.
William was all smiles as he jumped in the SES truck to explore.
It was a moment Gary couldn't have been happier to see, overjoyed to finally meet the teen after having missed the moment of his rescue due to work commitments.
"Outcomes like Will's motivate me to keep going", says Gary, who led 120 SES volunteers in the search.
"Seeing the family again was a really happy day, Will is a great kid and you can see how people see him as being an angel."
During those nightmarish days and nights of searching, Gary, 54, had even arranged for a caravan to be delivered for the family to use, so they had some privacy and space to sleep.
It was an act of kindness Penny will never forget.
"Everyone was doing all they could to help, it kept me going," she says.
"I just want to thank everyone involved, we are so grateful that Will is here with us."
The Callaghans hope to build a pool to aid William's therapy, and he will continue to need ongoing support. To donate to the family, visit gofundme.com/will-callaghan-support-fund