Katy is almost twelve years old and she has everything. Wonderful parents, a smart, supportive older sister, great friends, and a beautiful extended family that includes grandma, grandpa, aunts, and uncles, who are sometimes annoying, and sometimes not, as in all families. When Katy's sister is diagnosed with a serious illness, the whole household is turned on its head, with doctor's tests, appointments, fears, doubts, and bad moods. Katy has to learn to cope with a sister who was hit by the "evil creature," as she calls the illness. At the same time, Katy, together with her friends, deals with the trials of youth--a disappointing first love, a class queen who is not very nice, and a first kiss.