Citrons!

Carl is excited about starting a butterfly collection.

Carl realizes he has trouble listening when he's playing with an awesome collection. Can Sheldon teach him how to be a good listener?

Carl and Nico are arguing over who gets to have Roquette as their magic assistant, but that's not really what Roquette wants.

Veloursville Park is covered in trash. Yuck! Carl discovers a collection you don't keep: trash!

Carl accidentally breaks a gift meant for Sheldon's mom and has to learn to forgive himself while helping Sheldon find another gift.

Forest makes too many plans for the same day and leaves behind a string of disappointed friends.

Carl and Roquette build a spectacular marble run, but despite their many attempts, they can't get the marble to roll!

Sheldon can't wait for Carl to play his favorite beach game, but Carl is nervous. What if he doesn't do as well as his friends?

Lotta has lost her favorite blanket, and her friends are determined to help her find it.

Carl learns a new word: “Ribouldingue.” Will he be able to say it at the right time and in the right way?

When Carl remains frozen after Nico's fall, he confides in her to help her understand why he didn't know what to do.

When Sasha calls Lotta “the girl with headphones,” Lotta is determined to show him that she is much more than that.

Everyone is wary of the new kid after the commotion he caused in the playground.

When Lotta feels frustrated learning a new dance, she eventually realizes that it's perfectly normal for her to experience music in her own colorful way.

Sheldon hesitates to tell Carl that he no longer wants to play their favorite pirate game.