While on an expedition in Antarctica, the Count of Champignac makes an extraordinary discovery: a still-viable dinosaur egg!
Having brought the precious find back to his castle, he invites a few colleagues over - along with Spirou and Fantasio - and sets about hatching the egg.
But working towards scientific progress isn t easy when one is somewhat absent-minded... and saddled with a whimsical Marsupilami 'assistant'!
Soon, life in the village of Champignac becomes rather complicated...