Roland is the youngest of three boys, and a bit of a loner. It's his brothers against him, generally. One day, while he's wandering along the roadside looking at the hard rubbish put out for collection, he finds an interesting-looking screw-top tin. He takes the lid off, and suddenly a small girl is standing beside him. She follows him home. Roland doesn't realise at first that the girl is a genie, not even when she tells him her name is Eugenie. She wants to be his sister, but he's having none of that. His mum has warned all her sons that girls are subversive and dangerous - and that there are to be NO GIRLS in their rooms.
It takes a while for Roland to realise that all his wishes are coming true, and why. But he still really doesn't want Eugenie around, so puts her back in the tin. In the end, however, he realises that a little sister would be really useful ('No one else had ever wanted him for their brother, not even his real brothers. Then it would be two against two... ') So he makes a final wish...