Segment 1: Sea Snakes of Bird Island. In this exciting adventure, Jonathan travels to Manuk, a tiny, uninhabited volcanic island several hundred miles from the nearest populated island in Indonesia, on a mission to discover why the waters of this remote place are teeming with thousands of venomous sea snakes! Segment 2: A Manta Feeding Frenzy. At a remote atoll in the Maldives, Manta rays gather in large numbers for just a few weeks each year to feed on plankton that accumulates in a small lagoon. Will Jonathan manage to time his visit right and find the mantas?