Location: Deffry Vale High School, London, England, Earth
Enemies: The Krillitanes
Deffry Vale School, a normal, local high school. But not everything is as it seems. Sarah-Jane Smith decides to investigate the place, with her trusted (yet rusted) robotic dog K-9. But there she unravels a deeper mystery, as she is reunited with a face from her past. The Doctor, who left her behind many years ago, has returned, and everything about him is different from the Doctor that Sarah remembers...