Youthful, lighthearted, clever, and entertaining series, with black-and-white modern illustrations, plenty of humor, many mysteries, and quite a few comical situations. Penny is 10 years old and her dream is to become a detective. She sees mysteries and suspects everywhere: What's up with the bloodthirsty neighbors? Why has the school janitor transformed from sour and abrupt to a gentleman? And what is he preparing in his little room? What’s going on with the strange and grumpy man she accidentally met on the street? Penny knows many methods of solving crimes well, and she is equipped with the necessary tools!

Crime scene: Amusement park.

And the most unlikely detective gang is there: Penny, her best friend Ida, her second best friend Marie, and Flora, her former enemy. And of course, Justin, the bloodhound. When Penny's wallet goes missing, the girls consider it an accident. But Flora's phone and a bunch of other phones, watches, and wallets soon meet the same fate. Penny and her associates decide to solve the mystery. And Justin quickly discovers a clue. Which leads them into the haunted house ride...