The stories in Caitlin Horrocks’s masterful debut collection, This Is Not Your City (Sarabande, $15.95), start in familiar places and go into deftly imagined elsewheres. A woman feels uneasy while expecting her first child. Why? Because she can remember her own and others’ previous incarnations and recognizes the old soul in the new baby.  A story in the form of a term paper shifts yet again to become a high school senior’s poignant autobiography, documenting her mother’s illness and the family’s poverty. A couple on a cruise is by turns childless and the parents of a brood of overachievers—both smokescreens to deflect inquiries about their only son, born severely brain damaged. When pirates board the ship, it’s the least of the dramas going on here. Other characters find love, but not understanding, and work doggedly at jobs or relationships despite ambivalence. Widely published in the top literary journals, Horrocks, whose prose carves a clear, sharp picture of people of all ages and of places from the American Midwest to Finland, is a writer to watch.