Brewster, Maggie and Ginger talk about all the things they have to keep them warm in the snow. They notice a little robin and wonder 'How do birds keep warm in winter?' Brewster takes them all to the Arctic where they meet Snowflake the snow owl.

The friends play with Brewster's new telescope. They use it to look at the moon, but Carrick can only see half, which makes them wonder 'Where is the other half of the moon?' They travel to the moon and discover where the other half could be.

Brandon shows Brewster and Maggie his composter. They wonder 'Why do flies like to hang around stinky stuff?' Inside the composter they meet Mortimer Fly and his mother Mummy Fly, who explain that stinky places are ideal areas to lay eggs.

Brewster and the gang meet Cod Wriggles and ask 'why is the ocean salty?' They take a dive into the ocean and use their imaginations to come up with different scenarios before Cod explains that rivers and streams carry salt into the sea from the land.

Brewster is frightened when he hears thunder, and the friends ask, 'What makes the sound of thunder?' Up in the clouds, they meet Cloudy Nimbus who informs them that the clouds rub together and release their shock called lightening and that makes the loud sound.