Tonight Leo is counting the sleeps until Mum comes home, and he doesn't feel like doing much of anything. So Grandpa sets a small brown bulb on the table and tells him an old story: a mother who could make the whole world grow, the daughter she loved, and where all the flowers go when winter comes.

Where the flowers go in winter is one of the oldest questions, and the Greeks answered it with a story about a mother and a daughter. The mother, Demeter, made everything grow. Her daughter, Persephone, spent part of each year below the ground and part of it above, and the world went cold while she was gone and bloomed again when she came back. It was written down as the Homeric Hymn to Demeter more than two and a half thousand years ago. The old myth has darker corners, a kidnapping, a god of the underworld, a bargain over a pomegranate, and we have left all of those out. What we kept is its heart: a daughter who goes down to look after the sleeping seeds, a mother who waits, and a spring that always comes back.