Seventh-grader Eta Dorcas fears the worst when her fingertips glow blue after a birthday outing to an Iowa cave. She captures a cute weasel to be her pet. These two events become a third when the weasel speaks French and Eta learns the code to release a captured medieval knight from his furry body.
Ancient seafaring Greeks had captured the seventeen-year-old Scot and, when they failed to extract from him the location of gold hidden in a Highland's cave, evoked witchcraft to cast his soul upon the seven seas.
Named for the seventh letter of the Greek alphabet, Eta joins the young knight on a quest to reverse the curse.
All is not without turmoil. Eta's finger glow neither easily diagnosed nor reversed. Hawks, wolves, a raging woodland fire, and a neighbor boy with a birthday rifle hunt Eta's weasel-turned-teenage-boy.
With but three chances to undo the curse, Eta struggles to learn the key to three words given her cursed knight: Find the Girl.