The Secret of the Prince's Estate

Summer. The dacha. Vacation. For Masha, Dima, Nastya, and Petya, known as the Maple Leaf Brotherhood, this is no excuse for idleness. After all, something strange begins to happen in the village of Krasnye Gory right before their eyes.

In the abandoned estate of Prince Borsky, surrounded by gloomy legends, lights turn on at night. And then it turns out that someone is secretly digging tunnels there, as if searching for something hidden...

The young detectives come across an old diary of Prince Borsky himself. Inside is a yellowed map of the estate, marked with mysterious crosses. What do they mean? An exit to a hiding place? A location where treasure is buried? At the same time, heirs of an ancient lineage appear in the village - Prince and Princess Pozharsky. They clearly seem nervous and troubled by something.

Now the Maple Leaf Brotherhood has a new case. They have to decipher a message from the past, understand who is ahead of them, and navigate ancient dungeons that haven't been tread upon by human feet for the last hundred years.

This investigation will require them to show courage, resourcefulness, and true teamwork. After all, it's one thing to seek adventures by day, and quite another to face them at night in a dark labyrinth.