Frank and Joe are searching for their father in Europe, who went missing investigating a series of art robberies at a rock festival in Europe called Dracula's Castle in Transylvania where he ends up missing and the boys go in a merry romp to search for him as some people suspect he is dead. Nancy Drew ends up in the same hotel room as the boys do and a clash happens between the two of them but end up joining forces for the first time to solve the mystery. Their investigation leads them to the Dracula's Castle, where some strange going's on ensue.They meet up with a touring group of musicians led by Tim and Joe offers to sing in their group by paying them for him to sing at the festival in Dracula's Castle to search for their missing father. They meet up with the town's regular singer Alison Troy and he accepts them to be musical guests while Frank and Nancy tries to find any missing clues. They find Fenton in a coma. Then meet up with Inspector Stavlin who might be... Dracula? They encounter bats in their hotel rooms and victims with teeth marks in their necks which makes the story very suspenseful.