Meet Willa Waters, aged 8 . . . 33 . . . and 93. On one impossible day in 1965, eight-year-old Willa receives a mysterious box containing a jar of water and the instruction: ‘One ocean: plant in the backyard.’ So she does – and somehow creates an extraordinary time slip that allows her to visit her future selves. On one impossible day in 1990, Willa is 33 and a mother-of-two when her childhood self magically appears in her backyard. But she’s also a woman haunted by memories of her dark past – and is on the brink of a decision that will have tragic repercussions . . . On one impossible day in 2050, Willa is a silver-haired, gumboot-loving 93-year-old whose memory is fading fast. Yet she knows there’s something she has to remember, a warning she must give her past selves about a terrible event in 1990. If only she could recall what it was. Can the three Willas come together, to heal their past and save their future, before it’s too late?