During an internship on a film set in Romania, the three detectives investigate eerie occurrences at an old castle. They uncover a mystery surrounding a missing child and a mysterious amulet. The Carpathian Hound: In Rocky Beach, an art collector's house is supposedly haunted. When a valuable crystal figurine is stolen, the boys must find the thief among the eccentric residents. Isle of the Dead: A mysterious phone call leads the trio to the volcanic island of Makatao. There, they clash with the secret society Sphinx, which will stop at nothing to get its hands on an ancient treasure.