A chance encounter on Portobello Road incites an unsettling, magnetic attraction between Mary, a 75-year-old British spinster, and Cub, a 13-year-old Jamaican boy from Brixton. As dementia overtakes reality, Mary clings increasingly to phantoms and fantasies. But her macabre romance with Cub comes to a horrific climax, as white supremacy, poverty, and class conflict explode on the streets of London.