Matt Baker and Julia Bradbury head to the Thames Valley, on the doorstep of London but far away from the madding crowd. This picturesque countryside has at its heart the river that bears its name. Matt takes to the water with an Olympian to find out what makes Henley-on-Thames such a breeding ground for gold medal winning rowers. Meanwhile, Julia is at Burnham Beeches on the hunt for giant wood ants with an unusual defence mechanism which led to the discovery of formic acid. John Craven visits the Household Cavalry as they take part in an equine health survey launched by the charity Blue Cross. Elsewhere, Tom Heap is on the south west coast to find out why our seabirds are in decline; and down on the farm, Adam's Highland bull Eric is causing a bit of a stir.