It’s almost 45 years since a big cat native to the Americas was captured in the Scottish Highlands.
The female puma - later nicknamed Felicity - was caught by a farmer frustrated by a series of savage attacks on livestock.
He set a trap using a cage baited with a sheep's head.
But was the puma really to blame for the killings or an unwitting participant in an elaborate hoax, and why did big cat sightings continue after she was caught?
Iain says some people were sceptical of the reports while others convinced there was something out there.
He says: "It was a little like the Loch Ness Monster.
"You might or might not believe in it."
Iain says local police were interested "to a degree".
Then word came that a farmer, Ted Noble, had trapped a big cat.
Mr Noble had lost livestock to attacks himself and reported seeing a large cat stalking his Shetland ponies.
The media descended on Ted's farm.
"It was a circus," says Iain.
"There was this poor beast in a cage snarling and hissing at everybody and a crowd of journalists, photographers and cameramen all milling around.
"It was a bit bizarre."
Not everyone believed Felicity was behind the attacks.
There were a few red flags.
Experts described her as elderly, tame and overweight. She also had arthritis.
Some suggested she was a pet either abandoned - or even used to hoax Mr Noble.
Felicity was taken into the care of the Highland Wildlife Park near Aviemore.
Iain interviewed the park's owner, Eddie Orbell.
"Eddie said 'this beast hasn't been in the wild half an hour. It's been fed and well looked after'," says Iain.
"He cast considerable doubt she could have been haunting the Highlands for years."
Iain heard stories from the park of Felicity behaving like a household moggy.
"It allowed people to scratch it behind its ears and there's a story one of the keepers would walk around the park with Felicity draped around his shoulders," he says.
Felicity lived out the rest of her days at the park. She died in 1985.
After the Felicity's capture reported sighting of big cats continued almost unabated.
"We still regularly get fresh sightings," says Paul Macdonald of Scottish Big Cat Research.
The project has a network of 80 volunteers and has gathered more than 1,600 big cat sightings going back to 1947.
In recent times these encounters included:
Paul, a Scottish Borders-based sword-maker who grew up in Lochaber, helped to set up the group in 2019.
He has been fascinated by Scotland's mysterious cats since his own sighting in the late 1980s.
Paul says he and a friend were travelling by train near Glenfinnan when they spotted what he describes as a melanistic leopard, also known as a black panther.
He says: "It was about 4 to 5ft long in body, had a long tail and muscular rolling shoulders as it slowly slinked away."
Paul believes many of the big cats were pets dumped after the introduction of 1976's Dangerous Wild Animals Act.
"People used to have them in their flats," he says.
The law requires people to buy a licence and keep the animals in appropriate sized enclosures.
Paul says: "I think there were multiple release events by owners whose other option was to have the cats destroyed.
"An illicit trade in exotic animals since then have added to those releases."
Scotland's nature agency NatureScot advises on non-native mammals in the wild and has information on its website about how to report unusual species.
A spokesperson said: "While we receive one or two sightings of big cats a year, none of the reports submitted over the past 34 years have provided sufficient evidence to conclude that big cats were present.
"The last verified sighting of a big cat in the wild in Scotland was in 1980."