A nine-year-old boy receives a plastic Indian, a cupboard, and a little key for his birthday and finds himself involved in adventure when the Indian comes to life in the cupboard and befriends him.

In this third book about Omri and his magic cupboard, Omri and his friend Patrick must risk grownups' discovering their secret when they find themselves in need of a friend's toy plastic doctors to save wonded people from the dangerous world of the Old West which the cupboard enables them to enter.

As Omri, his father, and other members of his family learn more about the cupboard in his room, together and separately they are caught up in several dangerous adventures that reveal more about its powers.