Brødrene Dal og professor Drøvels hemmelighet.

The Dal brothers set off to search for Professor Drøvel, who disappeared during an expedition twenty years ago. They travel by canoe, Elvegris, and on their journey many strange and inexplicable things happen, which are depicted in sketches. Among other things, the brothers encounter an Indian tribe and a number of pirates, are chased by deadly mosquitoes, and accompany Dracula to the dentist.