It turns out that this incredibly beautiful mansion hides so many secrets and mysteries that it would be simply a crime not to solve them! Friends Holly, Tracy and Belinda, who founded their Detective Club, came here to work at an important business conference organized by Belinda's father. And now they have to work twice as hard: a crime has been committed in the mansion, the friends were the first to discover the evidence and now, until they find out what’s what, they won’t stop! Before this, Holly noticed a suspicious person who was interested in the alarm. Clearly, this is a spy. And no other way than he is most involved in the nightmare that is happening in this huge house...