It's fast, it's furious and it's just outside Scotland's capital. The Pentland Skyline Hill Race takes in virtually every peak in this striking landscape: 16 miles long and nearly 2000 metres of ascent. The fastest do it in just over two hours, so it's full on from the very start. Also on the show, we'll be finding out why one man chose to walk from Lands End to John o' Groats in a completely straight line. And, on a wild winter's day, we're heading into the Cairngorms with former speed skier turned photographer, Henry Iddon - not to race down the slopes but to capture an image that commemorates a mountain tragedy.