The Collector intimidates Jasper into giving him the key to the exhibit, but Trudy finds out and becomes suspicious. The Collector creeps into the library to examine the Exhibition, leading to a close shave for both Nina and Victor. Jerome and Alfie bet Eddie that he cannot convince Patricia to dance, and Eddie wins. Nina figures out how to cross the chasm, but when she runs to tell Fabian, she sees Joy kissing him. Upset, she flees to the tunnels while Jerome reads the letter that his father has sent to him and his sister from prison. Nina is angry with Fabian, but she shows him and Amber the crocodile beam, which they need to use to bridge the chasm. However, the quest becomes even more dangerous because Victor is now closer than ever to discovering the tunnels.

Jerome finds out that his dad wants him to visit in prison. Patricia softens her attitude towards Eddie and then finds out about his bet. Joy and Mara sign up for the school website. Amber and Fabian enlist Patricia and Alfie to help them fit the bridge across the chasm, but it almost falls in. Sibuna practices laying the beam, and Victor finds the lock in the cellar. Alfie fails to dump Amber while Patricia plans her revenge on Eddie. Jerome and Mara visit his father while Sibuna encounters a new danger at the chasm.

Victor and Vera hide in the cellar and see Nina exiting. Thus, the antechamber code is revealed. While Sibuna practices dodging pendulums, Patricia's revenge on Eddie backfires. As Sibuna enters the antechamber, they are shocked to find Victor standing there. Victor has been blinded by the beacon flash, though, and Sibuna only just manages to avoid him. Poppy finds out that her father wants to arrange a prison visit and that Jerome did not tell her. Sibuna crosses the chasm but then finds a dead end. Senkhara becomes angry at Nina and gives the mark to Amber, Patricia, and Alfie as well in vengeance. Vera is portrayed as being the Collector because the Collector sent the same message Vera sent to Jasper.