The Green Balloon goes on holiday! Lily-Rose, Ant, Cat, Nature Chris and Skipper the dog travel to Northern Ireland, where the children are going to be zoo keepers at Belfast Zoo for the week. Skipper takes Nature Chris on a walk, where they meet Green Balloon Club members Lynne and Amy and find out the legend of the Giant's Causeway. It's Jelly's first time in a sailing boat when she meets up with Robyn and Ben, who take her out exploring on Strangford Lough. And sisters Kathryn, Abby and Lucy introduce us to their pony Snoopy. Lily-Rose, Ant and Cat get their first taste of zoo life when they have to take the zoo register and they get to feed the ring-tailed lemurs. And of course the Green Balloon Club is never complete without a song - a special zoo song.