Kev and Sam are joined by Kev's two brothers for a loop hike in the Nelson Lakes National Park. Starting at the Sabine Hut on the shores of Lake Rotoroa, they head up the Sabine Valley to Rotomairewhenua, the lake with the clearest water in the world. They then head over Moss Pass into the D'Urville Valley and make their way back to the head of Lake Rotoroa finishing at the D'Urville Valley Hut.