What is Water?

Toby thinks for a while and asks: ‘What is water? 
That’s a difficult question.
After a while, dad says: ‘Wat is all around us.
In the ground, in the sky, in the sea.’
‘And in the tap,’ Toby says.
‘Yes, in the tap, too.’

A mushroom container sends father and son on a small voyage of discovery in the kitchen. You can fill the container with water, and freeze it. But it can turn back into water as well. Or  turn into steam, which disappears through the chimney. And then it comes back as rain. As water. Which you can put in the container.