Vinga dreams of the sea. She's going to be a sailor when she grows up, sailing to distant lands. At home, back in the city, Mum is sad and Dad has left for good. But here with Granddad on the island, all her problems feel far away. Summer goes on as usual, with porridge for breakfast, drinking rhubarb lemonade under the lilac tree and watching the sunset from 'her' cliff. But things are different now too. The heat vibrates during the day, and a girl with a black hat has started appearing. Her name is Ruth. The only thing they seem to have in common is their age and that they are both on the island for the summer. But spending time together, their friendship soon turns out to be something much more.