There are two hurdles of disbelief that readers of Rose Doyle's sixth novel must cross. First, that a recently-widowed Irishwoman left financially secure in a comfortable Dublin suburb with two successful grown-up kids would bother to up sticks and head for the US to seek out her dead husband's estranged family - out of simple curiosity. And second, that Seattle is a more dismal setting for a work of fiction than any small town in Ireland could ever be, even on a wet Friday in February. Doyle convinces us effortlessly of the latter, in a series of dripping snapshots of low cloud over Puget Sound; and this claustrophobic family saga ticks tidily along to an atmospheric, explosive and extremely messy conclusion on the city's dilapidated waterfront. In Secret Sin is a grittier book by far than Doyle's previous outings, and there are few laughs and precious little romance as Bridget Baldacci rummages in the gruesome dirty laundry of her husband's dreadful family, but at the end this reader, for one, was still looking doubtfully at that first hurdle.