”I am not a travel writer in any reasonable sense of the word,” confesses English travel writer Diski. No, indeed. In a prickly, haunting memoir detailing two American train trips — one across the South, one circling the country’s perimeter — the author seems bored silly when evoking the open prairie or the desert Southwest and rarely disembarks to explore life beyond the viewing windows. But as long as the events she describes get no more, or less, exotic than Diski hanging around Amtrak smoking cars (dubbed the ”sin bins”), Stranger makes for a mesmerizing journey. The author’s wittily rendered relationships with those she meets — manic retirees, gregarious gigolos, and drifters of all stripes — are set in heightened, suspended relief as they hurtle across America together.