Glitch has taken Tala on holiday to Slovenia's Postojna Caves, and she is looking forward to finding a rare creature called an olm for her class project. Ubercorn and Lars join them, with Lars interested in the caves' underground train system and rare animals. But when Glitch takes Tala and a group of unsuspecting tourists deep into the cave on the Grimbots's enlarged toy train, Lars has to race through the caves to protect them from falling stalactites.

Originally released by BBC Worldwide Learning, 2020. Streaming video file encoded with permission for digital streaming by Infobase on January 18, 2022.