Weatherman Derek Brockway is in Carmarthenshire to walk along a former railway line running from Cross Hands to Llanelli.
On his way he fulfils a boyhood ambition to drive a train and impresses members of the famous Tumble RFC with his kicking skills.
Meanwhile biologist Lizzie Daly gets up
close and personal to a massive bird of prey and astronomer Dr Jeni Millard uncovers the story of the pioneering Victorian woman who photographed the moon.