Posie Flump is bored and wants to play but all of the other Flumps are busy doing things. When she asks what they are doing they tell her but tell her it is a secret and to 'keep it under your hat' - but Posie is not wearing a hat.
Grandpa Flump is playing his Flumpet loudly, this puts Perkin in a bad mood. Ma tells Perkin to cheer up otherwise he will be 'under a Grey cloud all day'. It's true as a cloud follows Perkin everywhere - how to get rid of it?
Pootle is making a mess in the house looking for mislaid bits and bobs. So, Ma Flump gives him a pocket to put things in. Pa Flump gives him a strong magnet but soon he is coated in metal objects and falls asleep.
Perkin, Posie and Pootle Flump are riding the Flumpcycle. Pootle says he could ride it all the way to the Moon. When they ask Pa how far the Moon is he tells them they would need a rocket - so they build one of cardboard tubes.
Pootle and Posie are standing on their heads, Perkin comes along and shows them how to do proper exercises. All of The Flumps have ways of keeping fit - but Grandfather Flump soon wishes he hadn't tried to lift Pa's weights.
Everyone in the Flump household keeps losing things so they set-up a lost property box. The children first play 'Hunt the Thimble' then 'Hide and Seek' but then Mother comes and tells them that she can't find Grandpa anywhere.
Pootle is being very helpful lending a hand to first Ma baking in the kitchen, then Grandfather polishing his Flumpet and Perkin planting seeds. But he gets all tangled up when he tries to help Posie with her knitting.
The Flump children are bored and dream of doing something different. Ma, Pa and Grandpa all tell them stories of Flumps they wanted to be when they were younger. Eventually, the children realize that they are happy with their lot.
Grandfather Flump oversleeps and is the last to have breakfast, he suddenly remembers it is his birthday - but there are no cards or presents for him and no-one has wished him Happy Birthday. He sets out to jog their memories.
The three Flump children have all been given colorful balloons, but Pootle can't inflate his. He looks for a way to blow up the balloon. The Flumpet bursts the balloon, he gets another but puts too much air in and floats off.