In the second installment of Halley Harper, Science Girl Extraordinaire, 10 year old Halley believes science is magic, just like her friendship with Gracelyn. Until one day they can no longer be together. How will she be able to go back to her second summer of Camp Eureka without her best friend and partner in science?
At camp, Halley has to confront a new mean girl and try to survive a magic chemistry show that proves to be explosive. To make matters worse, Halley loses her diary where she wrote her inner most thoughts about her friends and the secret treasure of Camp Eureka. Can she save her friendship and locate her diary before it falls into the wrong hands?