Paul and Bob travel to Dorset to fish the River Frome in search of grayling. They last fished for grayling successfully, but this time they have found a stretch of river known for setting the British record — so hopes are high that they could catch something big. As the pair fish along this unspoilt stretch of river, they realise grayling aren't the only species roaming these waters. And later, they attempt mackerel fishing on Chesil Beach, close to the species' feeding peak at dusk.