Sports ace Franzi, bookworm Kim and fashionista Marie are best friends – and budding detectives. During the summer holidays, they take part in a theatre project based on Peter Pan. During rehearsals with the eccentric director Robert Wilhelms, strange noises suddenly start coming from the auditorium, the lights begin to flicker menacingly, costumes are cut up and a threatening message appears on the make-up mirror. Is there really a lonely phantom haunting the place, seeking revenge? But some of the other workshop participants are also behaving strangely. Who has a motive to harm the theatre? A new case for Franzi, Kim and Marie! Will BFF Detectives solve the mystery?