The little orphan mouse Célestine lives in the underground world of rodents. At the orphanage she learns to collect teeth from the scary world of big bears. During one of her tooth hunts she is nearly eaten by Ernest. An unlikely friendship eventually arises between the two, but being a friend of a bear does not prove to be completely trouble free.

Going to pick blackberries, Celestine discovers an old mill invaded by ivy. Ernest claims that the building is haunted, but instead of scaring Celestine, it perks his curiosity ...

Ernest has lost his accordion's button and Celestine is convinced that it is the Green Mouse, a mysterious rodent that recovers lost items, has it ...

Ernest is tired of being overseen by his neighbours. He has an idea of how he, along with Célestine and Bolero, can do something about it.

Ernest is sulking because his bees have begun producing bitter inedible honey. Célestine is in good humour since Madam Tulip's flowers are lovelier than ever.

The mice are preparing for their annual ball, which Célestine has been invited to for the first time.

Augustine boasts that he saw the famous monster running near the lake. Célestine and her friends ask Ernest to take them there immediately!

Ernest becomes a museum curator to allow Celestine to paint. When a painting is stolen, he is suspected!

Célestine and Ernest take in a little wild goose. Célestine would like to keep it, but maybe it would be better to listen to Ernest and teach it to fly?

Mr. Martin would like Ernest to play in his shop. Mr. Martin lends Ernest an old mechanical piano that's completely out of tune...

As soon as it freezes, the bears go into hibernation. Except for Ernest, who claims he’s accustomed to extreme temperatures.

Mrs. Tulip saw a rat hanging around her house! Is it really a rat or a big, mischievous mouse?

Ernest shows Célestine the stars and constellations. They're all named after animals…but none of them are named after the mouse! What a disgrace!

A new train that goes to the ocean has just opened in town. Célestine would love to go to the sea with Ernest, but the ticket is very expensive...

Bolero hits his head and can't remember anything! He thinks he's a mouse, then a duck... have you lost your head, Bolero?

Several objects are disappearing in town: Célestine's notebook, Boléro's hat, and even... the Green Mouse's cape! What's going on here?

Ernest is honored when the mayor asks him to sing the "Song of the Bears”. But when his voice starts acting up, who can replace him?

Augustin invites Célestine over to celebrate his birthday. But, how can Célestine celebrate her own? Nobody knows exactly when she was born…

All of the mouse children are leaving for vacation to go to camp. Celestine would like to go as well, but she's never been to camp before!

Mr. Martin and Mrs. Tulip are not very happy on New Year's Eve. Celestine wants to help, but…what surprises do they have in store?

Simeon, Celestine's stuffed penguin, has disappeared. The town is helping to search, but often, what we're looking for is right under our nose...

Ernest is sick and Célestine is taking care of him. But Ernest is acting like a child and wants to do things his own way!

Ernest and Célestine want to take his grandmother to a restaurant she loves. But to eat at such a fancy place, one must have good manners!