The events take place in a small town called Palava-le-Flot in 1998. Sandrine has always felt like she had the makings of a detective and managed to annoy the local law enforcement officers quite a bit. Now she decides to go undercover after a body is found in an amusement park. Sandrine infiltrates the crime scene disguised as a cotton candy vendor. It turns out that the bustling fairground can be a place where a dangerous criminal operates. The main heroine is determined to identify the killer. She's on a mission to catch a killer coaster.