What happens to the awkward octet during their week away from life's usual gravitational pull? Bouncy moments of semi-dysfunctional-family comedy. Sombre moments of loss and longing. Revelatory moments, as when the teenagers concede (briefly) that their parents may actually be reasoning human beings.
All the cast are vulnerable to shock and change: the man who refuses to engage properly with the world; the woman who watches children the way a snake watches a cat; the razor-sharp, desperately insecure adolescents, all sheen and sneer. Relations strain, splinter, survive.
There's abandoned enjoyment. The vinegar rocket is a huge success. So is little Benjy's variation on Scissors/Paper/Rock, called Wees/Poos/Sick. There's also visionary horror: the dead return, inimical and inexorable. Violence flares - a son slams his father against a wall; a daughter huddles filthy and shamed under a blanket.
The border landscape is beautiful and beautifully evoked. A storm is like the planet's end; a blue sky is a valediction.
But Haddon's focus is on personal landscapes, and especially on the family, "that slippery word, a star to every wandering bark". Funny and poignant, tender and resentful, it builds as the story advances, grained with good intentions and bad deeds.
It's a novel where technique threatens to overwhelm topic; where the author's virtuosity can irritate as well as impress. It contains much fine writing and some florid writing. There are no happy endings, but a few tentatively positive ones.
Oh, and I forgive Haddon for the moment when he describes a character as being reduced to two options: being dead or being in New Zealand.
David Hill is a Taranaki writer.