Jonah, Katherine, Chip, and Alex suddenly find themselves in 1483 at the Tower of London, where they discover that Chip and Alex are Prince Edward V and Richard of Shrewsbury, imprisoned by their uncle, King Richard III, but trying to repair history without knowing what is supposed to happen proves challenging. Author's note includes historical facts about the princes and king.

When a diphtheria epidemic hits her 1840 village, thirteen-year-old Jessie discovers it is actually a 1995 tourist site under unseen observation by heartless scientists, and it's up to Jessie to escape the village and save the lives of the dying children.