W.I.T.C.H. are five young girls (13-14 years old) chosen by the Oracle of Kandrakar to protect the world (and on occasion Kandrakar, which is in another dimension, and other worlds as well) from evil powers from other dimensions.
In Kandrakar, located somewhere where time and space do not exist, people are concerned about the wall which separates the evil from the good. After 1000 years of nothing the wall starts to weaken. The Oracle therefore assigns five girls as the Guardians of the wall. And that's how it begins. Will and the other newbie Taranee meet their classmates Irma, Cornelia, Hay Lin and Elyon. During the day all girls but Elyon discover their own unusual capabilities or other strange things. Meanwhile two sinister figures, called Vathek and Cedric, are out to destroy Will during Halloween. Thanks to the special effects by Uriah this won't happen. Cedric lays a snare on Elyon and they make an appointment. That night all five girls dream about the same locket, which is showed the next day by Hay Lin's grandmother. She clarifies their powers and gives Will the Heart of Kandrakar. Will makes use of it the same evening as she gets trapped with Irma and Hay Lin. They transform the first time and they close the first portal.