 Zammo and Jonah have been cleaning up the stickers, including ones mysteriously found on the school trophies. Fay, Annette and Belinda are told tales about the service tunnels by the workmen. Annette has a go at Fay for being too goody-goody. She challenges Fay to go spelunking with her in the service tunnels. After school, the girls have a row, and Fay storms off, but Belinda stays to follow Annette. Once underground, it s Belinda who seems to have taken charge. While the girls get lost, thieves have broken in under Gripper s instructions, in search of the trophy cabinet. As the girls finally escape, they leave the floor hatch open - and the thieves fall through and are trapped...