There will come a day when your children start to ask you questions about your own childhood. Everyone likes to talk about themselves, so it may be a few minutes before you realise that it's not exactly you they're asking about. Your past has become The Past. You're history. It's a bitter moment, all the more bitter if you belong to my generation. My parents could at least regale me with tales of the Blitz, the evacuation, war hero fathers returning from the sea. What tale did I have to tell? Decimalisation.

Mary O'Hara, the heroine of Roddy Doyle's beautiful new novel, doesn't ask about the past: it comes up and taps her on the shoulder in the shape of the ghost of her great-grandmother, Tansey. Mary's grandmother Emer is ill, about to die, and Tansey has a message for her. Mary's mother, Scarlet, has to help her daughter pass on that message. It's a story about four generations of women and what they have to say to each other. The men are far in the background, busy at their PlayStations. In one very funny scene, Mary's brothers do see Tansey's ghost, and leave the room  scared not because she's a ghost, but because there are too many women in a confined space.

This is also a story about death and how to prepare for it. Children's literature is going through a bit of a deathsploitation phase at the moment. Book lists are groaning with the cries of the dying and the undead. But A Greyhound of a Girl is different, and the difference is Tansey. Opinionated, easy-going, profoundly unspooky, Tansey is the best ghost since Christmas Past. Her casual attitude to the business of haunting brilliantly embodies the book's theme  that what lives on is not ectoplasm, but family. What will survive of us is love.

It's a measure of Doyle's mastery that he doesn't let her run away with the story, but leaves plenty of room for the other three women. This is an uncluttered book, though you sense that its luminous simplicity was only achieved by spending hours and hours bagging up all the unnecessary stuff and hauling it to the dump. Yes, they go on a road trip, but only down to the seaside to buy ice-cream. And what an ice-cream. One of the virtues of simplicity is that it provides a great backdrop for the moments of exuberance. I won't spoil it for you; I'll just say that Tansey's entrance with the ice-cream is an immortal moment.

The book's simplicity comes from the fact that, like the Barrytown trilogy, it is very dialogue-driven. It's a reminder that Doyle is one of the best writers of dialogue there has ever been. A Greyhound of a Girl has all that Barrytown strut and swagger. No, not swagger  sway. It dances. It dances on the grave.

Frank Cottrell Boyce's The Unforgotten Coat is published by Walker.