Think of the Arctic, and you probably picture a landscape thickly blanketed by ice and snow. Yet while four-fifths of Greenland’s surface is covered in ice, year-round, a strip on the country’s western coastline remains green – for part of the year, at least.

Presenter Horatio Clare, producer Jeremy Evans and sound recordist Andy Fell

It’s here, 40 miles north of the Arctic Circle, that you find the Arctic Circle Trail: a remote hiking route that starts in the fishing port of Sisimiut and snakes inland to Kangerlussuaq through a dramatic landscape of mountains, lakes and marshland.

For Christmas 2019, author Horatio Clare and a small team from BBC Radio 3 made the long trip north to record the experience of walking the trail. Setting out in early October, they'd be among the last people to make the journey before winter arrived to cover the path with snow.

The forecast was ideal, with daytime temperatures well above freezing. Best of all, Horatio and his producers would have the trail largely to themselves.

Or would they?

A week or so before their due departure date, the team received word that a polar bear had been spotted on their proposed route. They were going to have to call in some help.