Since her 2001 Booker Prize-nominated debut novel, "The Dark Room," British-born author Rachel Seiffert continues to go from strength to strength. In her last book, "Afterwards" (2007), a killing in Northern Island casts a cold shadow over a couple's relationship. Pain from the Troubles is felt once again in Seiffert's latest novel, "The Walk Home," a book as grim as its predecessor but flecked with moments of hope and humanity.

The main events of the novel take place at the end of the 20th century and the beginning of this one. We follow the divided loyalties and disintegrating love within a Protestant family on a Glasgow housing estate. Lindsey, who has fled Ireland and her hard-line father, is keen to make a new start in Scotland with little son Stevie and husband Graham. But she soon learns that her adoptive home is just as polluted by religious tension as her homeland. Despite her pleas, and her mother-in-law Brenda's admonitions, Graham is tugged away from his family and lured into a marching band that has connections to Belfast paramilitaries.

Intersecting this timeline of Stevie growing up while his parents' marriage breaks down are scattered sections dated "Now, or thereabouts." Here we meet a group of Polish builders in Glasgow, together with their latest recruit — a scrawny and scruffy teenage Stevie. Seiffert snags our curiosity and keeps us turning the pages, eager for answers: Why is Stevie now living rough? What has happened to his family, the one we are simultaneously reading about?

By the time Seiffert fills us in, we have encountered our fair share of defiantly independent characters who have cut themselves off from communities and loved ones to go it alone. Seiffert makes a clever contrast between the Polish migrants building for a better future and Lindsey stranded in her tower block fueled by "dreams of elsewhere." She is Seiffert's strongest character, her red hair matching her fiery personality. A close second is Eric, Graham's uncle, a reclusive widower who spends his days sketching morbid pictures until unlikely soul-mate Lindsey draws him out of his shell and back into the world. Haunting the whole novel is the ghost of Papa Robert, a fearsome patriarch with clenched fists "like meat boiled in brine," whose dogmatic opinions created the first of many fractures in the family.

"The Walk Home" is as flinty and gritty as its characters and their vernacular. Seiffert's last leg is perhaps a stretch too far that ekes out more of the same and tells us nothing new. Indeed, for some readers the entire book may feel like too great a distance to cover: dead-end lives stuck in dead-end jobs while "guns and men and malice" pass back and forth between Ulster and Glasgow. However, Seiffert's tragedy grips while it disturbs and its emotional punch makes it worth persevering until her bitter end.

Malcolm Forbes has written for the Times Literary Supplement, the Economist and the Daily Beast. He lives in Edinburgh.