The Susurrus

A clever and playful celebration of the things we can hear, can't see, but can imagine!

'Listen. Can you hear the susurrus?' said Grandma.
'What's a susurrus?' asked Frankie.

Frankie doesn't know what a susurrus is. She knows it not it's not a platypus, an octopus, or even a kind of saurus. So Frankie searches for the susurrus, while her friend Andy has suggestions as to what a susurrus might be. Everyone has a go at guessing what a susurrus is.
But no one has ever seen one.
What is a susurrus?
Frankie now knows.
Do you?