It is a mummy's hand that is held as a good-luck charm by the books' protagonist, Gabe Sabry.
Gabe bought the hand at a garage sale for $2. The kid that sold the hand to Gabe told him it is called The Summoner and it is used to summon evil spirits. Gabe does not believe that the hand is actually magical, but is intrigued by the possibility that it might be real.
In The Great Pyramid, Gabe learns from Ahmed that the hand is the actual hand of the ancient Priestess, Khala.
The Summoner is a mummy's hand. Gabe describes the hand as small and says it is the size of a child's hand. It is wrapped up in brown papery gauze.
The hand makes mummies come to life. Gabe pulls the hand out without thinking when he is in trouble and holds it high up in the air. It makes long-dead mummies come to life and come to his aid. Because Gabe says he was not thinking and does not know why he pulled the hand out, it can be inferred that the hand has the ability to persuade its owner. The hand also seems to move on its own at least as portrayed in the television adaptation of Return of the Mummy.
- In the television adaptation of Return of the Mummy, Gabe found The Summoner at the airport.