It is believed a fascination with rabbits the one-time city dog shared with her fellow canines took her just one step too far -- over a bank, several metres down the face of a gorge, and, fortuitously, into a tree, where she remained trapped and yelping for the rest of the night.
The Fire Service was contacted and started putting together a plan for a morning rescue.
Senior Station Office Bruno Saathof said he needed approval for a team of six who had sufficient skills to traverse the cliff face. And there was also the travelling time -- at least half an hour each way from the Hastings station plus the time to carry out the rescue.
Farmer Andrew Mouat, Ms Chalmers' ex-partner and father of their children, said that in the morning he could see Matilda "stuck" in a tree on a face above the Poporangi Stream, locally known as the Ohara, about 2km upstream of the junction with the Ngaruroro River.
As he spoke to the Fire Service about 7.30am, Mr Saathof could hear the yelping in the background and the rescue operation was confirmed.
But in the meantime Matilda had freed herself.
"A few minutes later she turned up here, out in the paddocks," Mr Mouat said.
"She looked a bit confused but she's all right. I think she fell out of the tree. It would have been too steep to climb back, so she'd probably made her way around the gorge and back up. I'd say she would have taken a significant tumble," he added.
Overwhelmed by the Fire Service response, Ms Chalmers said, "Oh my goodness, I didn't really expect it. I was wondering what we were going to do.
"I went up to the house to ring them, but they were almost here."
But it was too late to turn back the rescue crew, who arrived soon afterwards to find Matilda happily back home with children Jonathon Mouat, 5, and sister Tabitha, 7, before they headed off for the day at Kereru School.
It became the morning talk as most of the 28 pupils championed the survival of the Matilda now back in their midst.
"The kids all know her," said Ms Chalmers.
