Have you ever seen the sky under the ground? Arvin did He used to think every Sunday was the same until the day he met his tour guide, Arzu. Arzu is a lively tour guide with cool shoes, and she takes Arvin to New Zealand to see the Waitomo Glowworm Caves. These tiny, shiny creatures expand Arvin's world, and this trip certainly turns Arvin's boring Sunday into the adventure of a lifetime.