Since long ago, there have been two separate worlds—Earth as known by humans, and Metamoor, where spirits and fantastic creatures reside. Due to Metamoor's power-hungry ruler, Prince Phobos, a veil between the two planets was created to prevent him from infiltrating Earth. Watching over them is a council of powerful spirits from Kandrakar, a realm located between the two worlds. However, the veil has begun to weaken, leaving the council to rely on the arrival of the legendary Guardians of Kandrakar.

Meanwhile, on Earth, 14-year-old Wilhelmina "Will" Vandom has recently moved to the city of Heatherfield. Following the strange occurrences starting from her arrival all the way up to her new school's Halloween party, Will soon learns that she has been chosen as the leader of the new Guardians of Kandrakar and is given a mystical crystal, the Heart of Kandrakar. As for her fellow Guardians, they happen to be her schoolmates at Sheffield Institute, each possessing a natural affinity with the elements of water, fire, earth, and wind. These are Irma Lair, Taranee Cook, Cornelia Hale, and Hay Lin, respectively.

Together, these five girls form the group "W.I.T.C.H."—will they be able to protect the Earth from Prince Phobos' schemes?