On a morning commuter train in New Zealand's capital city, Wellington, the lives of three people briefly intersect. Sally is a 17-year-old, tentatively stepping into womanhood. Brendan is a middle-aged widower, living in the shadow of his wife's death. Tamas is a Hungarian immigrant, missing his wife and child as he struggles to begin a new life far from home. Meanwhile, in a nondescript building near Dunedin's Otago University, Farida translates messages for the security services and catches glimpses of a plot that could threaten them all.