The Summoning, by Lynne Ewing, is the first book in the author's Sisters of Isis series. The novel introduces three teenage girls who are leading normal lives in present-day Washington, D.C. until they learn that they are descendants of ancient Egyptian pharaohs and they have been tasked with saving the world from the evil Cult of Anubis.

The book opens with Sudi, the novel's main character, trying to shake off an apparent dream as she finds herself waking up in her front yard. While she can dismiss the incident as a case of sleepwalking, she finds it harder to explain the brass snake she finds in her bed the following morning. Later that day, she receives an invitation she believes is from Scott, a boy she likes, but when she arrives at the designated restaurant, she finds a young man named Abdel instead. Abdel tells Sudi and two other girls, Meri and Dalila, that they are the descendants, of Egypt's divine pharaohs. Therefore, they are the only ones with the power to defeat the Cult of Anubis, which plans to destroy the bloodline of Horus and turn the universe into chaos. They dismiss Abdel's story as an elaborate joke and return to their lives, but the following day, Sudi is suddenly able to read Egyptian hieroglyphs and finds herself trapped in a museum and talking with a phantom who appears before her. When she uses an incantation on a papyrus given to her by Abdel and transforms into a bird, she contacts Meri and Dalila. She learns that they have also been experiencing similar events.

Finally accepting their destiny, the girls begin learning to use their powers, and not a moment too soon, as they are soon attacked by the jackal-headed god Anubis and narrowly escape death at the gates of eternity. Later they meet a mummy who has been sent to kill them, but falls in love with Sudi instead, and rescue Scott, who has been kidnapped by the cult and had his soul replaced with that of a demon. At the same time, they try to carry on normal lives with school, families, and boys, while forming a close bond as the Sisters of Isis.