Nancy Springer was born in Montclair, New Jersey on July 5, 1948. She received a degree in English literature from Gettysburg College in 1970. She has written about 40 books for children, young adults, and adults including the Sea King Trilogy, the Tales of Rowan Hood series, the Book of Isle Trilogy, and the Enola Holmes Mystery series. She has won numerous awards including the James Tiptree, Jr. Award, the Joan Fassler Memorial Book Award, and two Edgar Allen Poe Awards.
Katherine Kellgren was born in New York City in 1969. She studied at the British American Drama Academy and the London Academy of Music and Dramatic Art (LAMDA). After graduating from LAMDA, she appeared on stage in London, New York, and Frankfurt. She narrated more than 250 audiobooks and won thirteen Audie Awards including five for best female narrator. She died from cancer on January 10, 2018 at the age of 48.