Visiting Zion National Park with his family, twelve-year-old Jack encounters two mysteries, the strange behavior of a band of wild mustangs and the possibly sinister actions of his new foster brother, a Shoshone boy.

Avery Donaldson and her three best friends are happy to be at Storm Cliff Stables for the summer, especially since gold medalist Anna Wainwright is supposed to be there to give riding lessons--but Anna is nowhere to be found, and Avery is convinced something has happened to her hero.

There is a new girl, Cassidy, at Storm Cliff, and she seems out of place at a riding stable because she knows nothing about horses and is even a little afraid of them--so Ryleigh sets out to solve the mystery of just who Cassidy is and what she is doing at the camp.

Khadija is missing her family who are in Pakistan, but when Aunt Jane announces that she is marrying her long time boyfriend, Clyde, Khadija assumes the role of wedding planner--but counselor Layla is behaving strangely and Khadija is convinced that she is planning to sabotage the wedding.

Twelve-year-old CeCe Monroe is enrolled at Storm Cliff Stables as Cassidy because she does not want the other girls to know that she is an actress, so when Aunt Jane asks her to assist with the movie that is to be filmed at the stables she is mostly afraid of blowing her cover--but when she realizes that the movie man calling himself Paul Martino is not the man she knows, she finds herself cast in the role of detective.