After spending the morning pretending to build a skyscraper, the children decide to go on a hike to Inis Spraoi's oldest building, the mound at Two-Knocks.
The class are being measured by Mr O'Dear to see how much they've grown. They're all getting bigger, but their poor plant isn't growing.
The children have just arrived at the school when Conor announces that he's lost his Captain Smelly doll. After a quick search he turns up inside Conor's hood. Crisis averted, the group head off on a long hike to the Foggy Isthmus.