The Countryfile team explores the Brecon Beacons. Matt Baker discovers geocaching, a treasure hunt with a modern twist, and meets an artist whose canvas is the night sky. Helen Skelton is sheep trekking across the landscape and taking part in a rather muddy fish rescue. Sean Fletcher jumps on his bike to meet the farmers who have taken diversification to the extreme, and Adam Henson finds out about a cancer cure for man's best friend. Tom Heap asks how safe horses and riders really are on country roads and if more should be done to protect them.