William Warner Sleator III was born on February 13, 1945. Sleator says that he began writing when very young and that even then he was interested in the stranger aspects of life. Though raised among a family of scientists, the young author was interested in the arts, becoming a pianist, composer, and writer. Perhaps his combination of interests in art and science led to his interest in science fiction, which he read avidly.

By high school, he was composing music that reflected his preoccupation with the macabre, giving his works titles such as "Guillotines in Springtime." He entered Harvard as a music major, though he later admitted that he was miserable at Harvard, with his unhappiness reflected in unhappy compositions. He seems to have been very productive while in college, writing musical scores for school dramatic productions and a multi-volume journal. While at Harvard, his artistic interests seem to have taken a significant turn, because he changed his major to English before graduating in 1967.

Sleator moved to England for a time to study musical composition while working for the Royal Ballet School as a pianist. He had a fortuitous event while in England, staying in a cottage in the woods that had been used as a pest house for people with smallpox. The cottage's walls even had graffiti on them from the 1700s. His stay at the cottage was the inspiration for his first published young adult book Blackbriar. When he moved back to the United States, he took a job as a pianist with the Boston Ballet, traveling with the company for nine years. He says he has voluminous notes in his journal about bizarre happenings with the company such as Giselle's house tipping over and knocking out a dancer. Someday, Sleator once noted, he hopes to turn his experiences with the ballet company into a book. During the nine years with the ballet company, writing took up increasing amounts of his time, and he finally quit his job so that he could concentrate on writing books.

Sleator's first two novels for young adults, Blackbriar and Run, were based on his real life experiences, and he continues to be inspired by his personal experiences. For instance, the author lives part of each year in Boston and part in Thailand, leading him to write about Thailand in The Spirit House (see separate entry in Volume 10) and Dangerous Wishes (see separate entry in Volume 9). He also says that he bases his characters on real people, which may explain Rewind's dedication: "this book is for Paul Rhode, who did grow up to be an artist."