Annie's Uncle Marco goes on one of his mysterious trips, leaving her in charge of two sealed boxes on one condition: she must not open either one while he is away. But she is tempted... and soon she has unleashed the unspeakable. The creatures inside the box are crab-like and grotesque. And they possess a power Annie could never have imagined: the power to transmute time.
William Warner Sleator III (1945–2011), known as William Sleator, was an American science fiction author who wrote primarily young adult novels but also wrote for younger readers. His books typically deal with adolescents coming across a peculiar phenomenon related to an element of theoretical science, then trying to deal with the situation. The theme of family relationships, especially between siblings, is frequently intertwined with the science fiction plotline.
Due to the suspenseful and often eerie nature of some of his works, Sleator has been compared to young-adult horror writer R. L. Stine. Others cite a strong resemblance to the paranoid, dream-like style of Franz Kafka, which is most notable in House of Stairs, one of Sleator's most powerful novels.
William Sleator. Wikipedia.