Fire burns throughout this novel, as the blazes set by the arsonist of the title are matched by the white heat of a passionate love affair and the smouldering resentment of a less-than-happy marriage.

The emotional kindling set alight for Miller's central character Frankie is the result of falling for a man with whom, for perhaps the first time in her life, there is a chance of settling down. After 15 years as an aid worker in East Africa, Frankie has returned to visit her academic parents in New Hampshire, where they have recently retired permanently to their summer house.

Bruised from years of short-lived affairs and constant partings, Frankie is a self-confessed "manizer", moving easily from one lover to the next. This home visit might be simply one more long vacation as she regathers her strength, or it might be her return for good; she cannot be sure. If nothing else, the sudden decline of her father, and her mother Sylvia's distress, mean she will be staying for longer than usual.

When she meets the local newspaper owner, Bud, a former Washington political correspondent turned small-town journalist, she is wary, then reckless, embarking on a relationship that feels more solid than usual. Regardless, she never lets Bud or herself forget that she is not here to stay. Even if she does not go back to Africa, work will take her to New York which, from the perspective of rural Pomeroy, feels almost as far away. Not surprisingly, cracks soon appear in this highly-charged liaison.

The arsonist begins his work on the first page, his tail-lights witnessed by Frankie in the early hours of the morning as, wakened by jetlag, she takes a walk in the dark. She is not aware until later that the empty house up the road has been burned to the ground and the car that passed her was that of the criminal.

Miller allows the town's anxiety to deepen, as the first fire is followed by another, and another, always targeting the summer house people, most of whom have not yet arrived for the season, or if they have, return to find their place torched while they've been out. Slowly, sickeningly, the community realises it is under siege. With that realisation comes another, almost as frightening: the possibility that war is being waged on the incomers, the ever-migrating non-locals, with money, and free time, and expensive clothes.

Miller is a skilful storyteller, never better than when evoking the spirit of a place and the tensions between neighbours. The chapter where the local fire officer and police chief try to calm panic at a public meeting is pin sharp, her ear for dialogue acute, her eye for character as told in a beer belly or squeaky voice a real pleasure to behold. Similarly, in a fleeting encounter in the local grocery store, she highlights the main faultline of the town, when a summer householder laughs at herself for thinking her larder was stocked with wine. "And then I looked on the shelf and realized that that was in Connecticut, and that I had absolutely not a drop here!" The other customers laugh with her, but once she has left the shop, one remarks: "That must just be so awful, having two houses to keep track of."

A veteran novelist, with nine novels behind her, two of which have been filmed (The Good Mother and Inventing the Abbotts), Miller's writing is deceptively easy, although her attention to domestic detail is excessive, adding an unnecessary weight of description. Despite this the story flows effortlessly, but beneath her often prosaic surface, passion, fury and bitterness roil, forming the main ingredients in this novel, as in her earlier work.

When the seeming idyll of New Hampshire is shattered, Miller addresses the politics and resentments of a town where there is constant flux and an invisible but marked social divide that is felt most strongly by the locals. In the character of Frankie, meanwhile, she explores another gulf, the chasm between the poverty of Africa and America's wealth. When set against the moral value of her aid work, the concerns of Pomeroy's inhabitants, indeed the worries of everyone in her orbit, seem trivial. How to reconcile these competing demands is, as this novel hints, as difficult as splitting the atom. Possibly it may be harder, since it has yet to be done.

As if this were not enough material for Miller, she adds the most powerful element of the novel in the shape of Sylvia's relationship with Frankie's father. Where the daughter's love affair feels a little hollow and contrived, set up for the purposes of plot, Sylvia and Alfie's long and imperfect marriage rings painfully true, Sylvia's interests subsumed in years past to her husband's more important work, and now to his desire to retreat to the country.

For this reader, The Arsonist would be more persuasive and less self-conscious, if it had not included the rather too obvious and starkly portrayed issues Frankie brings with her. These make the novel feel as if it is waging a campaign to calibrate what matters in life, even to those who on the surface appear to have everything they need. At the same time, she casts doubt on the altruism of aid work. This would be a fascinating subject for fiction, but not when dealt with in this perfunctory manner. These flaws apart, there are many satisfactions in The Arsonist. Not least is its nuanced and realistic portrayal of small-town society, a way of life that demands every bit as much commitment, Miller seems to suggest, as the big city, or the self-sacrificing job.