As the sky darkened, two women nervously crept through Myrtleford.
Hearts thumping they looked around furtively to check the coast was clear, quickly making their way through the park to hide in the shadow of the bridge.
Unlike most late-night vandals The Crackpots, as they'd come to be known, weren't out to destroy.
The two crafty friends, both "on the other side of 50", were instead on a mission to enact their own little mosaic rebellion after years of being well-behaved citizens.
Crackpot One, as she calls herself, defiantly plastered her mosaic fish in full sight - an unabashed challenge to authority.
But Crackpot Two hid herself and her mosaic among the rocks, certain they'd be sprung at any moment.
They worked fast and soon their night of crafty rebellion was over.
But the real magic was just beginning.
Regulars along the walking path began stopping each other to point out the mosaics, so The Crackpots made a couple more, and before long the mosaic mystery was drawing children and adults alike out from their houses.
The town was on the hunt; for the mosaics, and the culprits.
"I still can't get over it," Crackpot One says.
"It amazes me people are so interested."
There are more than 40 separate mosaics spread through Rotary and Apex parks (the giant fish mural being counted as one), with more to come. The Crackpots won't reveal the exact number of mosaics they've made or their locations because, like their anonymity, the mystery is all part of the magic.
"It's not about seeing everything at once," Crackpot One says.
"People ask us for lists or ask where something is.
"But we just say keep walking, keep looking. It's evolving so people know there'll be something new coming."
"(One regular) he's very distinctive," Crackpot Two says.
"He's a tall man with a cap on and a high-vis' vest so I made a mosaic of him," .
"He was actually tickled (when he saw it) because he'd been a big supporter.
"He's very shy but he'll talk to people and tell them about the mosaics, he's been one of our biggest promoters."
The pair have known each other about 20 years and thought of the mosaic idea while on a girls' trip.
"We've been mosaicing for about 15 years and our gardens are getting a bit full of pots and things," Crackpot Two says.
"We were on a girls weekend and thought we'd do something a bit naughty.
"We'd never broken the law before."
Eventually, as the project grew momentum, the pair decided they needed to fess up to what they'd done and contact Alpine Council.
Luckily for The Crackpots, both the mayor and the general manager are regular trail walkers.
"We actually spoke to someone over in Kyneton about mosaic bombing when we were on the girls' trip," Crackpot One says.
"She said 'well, first of all you have to get your council on board and your arts community on board and then your local chamber of commerce' and we got in the car and said 'crap, that doesn't sound like fun'.
"I guess we were fortunate the local mayor, who happens to be an ex-policeman, has foresight and a bit of commonsense about him.
"He realised more people were walking the trail and bringing their grandchildren out for something they can do together, outside of screens."
A Myrtleford Mosaic Trail brochure is now available at the town's visitor information centre for a gold coin donation, which goes to Friends of LaclutaWangaratta.
The Lions Club has also provided The Crackpots with a grant to cover the cost of grout.
Although the powers-that-be might know who is behind the project, the women's attempts to keep their identities secret have led to some unusual experiences.
"We always get sprung but they love it, then we say 'shhh don't say anything'," Crackpot One laughs.
"I was doing one on dusk and had my headlamp on when my battery died, so I had to finish it off with braille.
"I was in the paddock and there was an electric fence so I was trying to get back out in the dark, hoping I didn't stand on a snake or get booted by the electric fence."
A single mosaic can take anywhere from an hour to eight hours to complete, depending on its complexity.
But for The Crackpots, it's a labour of love, a chance to get out into nature and to spend time laughing together.
They also enjoy promoting the reuse, reduce, recycle idea of sustainability by turning broken objects into art.
"I'm a bit more throw it together and see how it looks, but Crackpot Two is a bit more exacting," Crackpot One says.
"We do well, particularly if we work together because if I'm with her I'm far more careful because I like her stuff and Crackpot Two likes my stuff (so is a bit more adventurous)."
The pair are looking to extend their mosaic trail through the town.
They have already received some specific requests from businesses and regular trail walkers who have uncovered their secret identities.
But despite going straight and turning their back of their "criminal" ways, The Crackpots are having as much fun as ever as they anonymously beautify the town.
"I'm continually amazed, people are very thankful," Crackpot One says.
"Our housework isn't being done but no one thanks you for doing that," Crackpot Two adds.
The pair never imagined their one night of rebellion would turn into something so big, but say the trail is a gift to Myrtleford from two Crackpots, with love.
To follow The Crackpot's journey and to donate broken crockery or odds and ends, visit the Myrtleford Mosaic Trail Facebook page or pick up a brochure at the Myrtleford Visitors Centre.