The crunch of gravel and the crash of the front door.
"Go and show your Mum," he says.
"Mum, mummy, look what we found at the beach!"
I rest my book on the arm of the sofa and resign my peace to the scrap-heap.
Tom bursts in, still wrapped in his blue overcoat and smelling of fresh air. In his hand is a rock, smoothed like a skimming stone but too big. I'm surprised he can hold it in one hand.
"What is it, darling? Come on, take your coat off and tell me."