Deffry Vale High School is haunted by strange, bat-like creatures at night. When the Tenth Doctor investigates, he finds an old friend, Sarah Jane Smith, already working undercover. This is mark the first time Sarah Jane Smith and K9 Mark III meets Rose, Mickey, Atem, his universal group of friends/allies, Diggs, Catherine, Seamus, Mewsette, Jaune Tom and Robespierre
