The ABC Murders (2018)

This episode features a visit to the slopes of the Brecon Beacons, where hill farmer Garry Williams and his family's flock needs to be brought down from the mountains for lambing. Meanwhile, in Snowdonia, climbers John Crook and Dafydd Williams, who climb all over the world, but are always drawn back to the Carneddau mountain range on their doorstep, attempt a first climb of the Kirkus route on Pen yr Ole Wen - following in the footsteps of pioneering mountaineer Colin Kirkus.