Overview: Gladiloli loses her diamond engagement ring in the ocean, when holidaying at the seaside with the Chief Gnome. So, the Chief Gnome calls Gordon away from his garden to dive in and recover it. Gordon and Andrew discover the most amazing underwater garden in the ocean, but find it very hard to get Gladioli’s ring back. It’s in the possession of a couple of angry sea slugs, called Ron and Don, who don’t like underwater tourists and have some very unusual ransom requests!