The Clangers are getting ready for a visit from the Hoot planet.
They want to make the Hoots feel welcome so Tiny Clanger is making up a lovely welcoming tune for the music trees to play and Granny Clanger is knitting some bunting to decorate the Clangers' little blue planet. Granny Clanger runs out of wool, so she sends Small Clanger and Baby Soup Dragon to get some from her wool cupboard.
Small and Baby Soup Dragon go inside and fill up Granny Clangers wool bag but they get distracted playing a chasing game. They forget all about Granny Clangers wool until they hear the sound of the Hoot planet approaching, when they suddenly remember.
They need a quick way to get the wool to Granny Clanger, so they throw the wool up into the curious tunnel that can transport things super-quickly to the planet surface and beyond. When they get back to Granny Clanger, they find the wool hasn't appeared. Will they find the wool before the Hoots arrive?