Pulse opens on the rock and ice of Greenland, where geologist Stephen Mojzsis shares a new theory on how water first arrived on Planet Earth. See a dragonfly's incredible journey from India to Africa – the world's longest insect migration. Meet the Munoz family, who use cutting edge time-lapse rigs to show the rare spectacle of deserts around the world exploding from barren wastelands into rich carpets of flowers. But the pulse is under threat.