James Burke introduces the highlights of Astronauts Young and Duke's last day on the moon, including their exploration of the giant boulders around North Ray Crater, direct from the BBC's studio at Mission Control, with comment from: Dr Eugene Shoemaker, former Head of NASA's Geology Section and Dr Stuart Agrell (Cambridge University), Dr Geoffrey Eglinton (Bristol University), NASA Principal Investigators and comment from the astronauts and scientists at the Manned Spacecraft Center.