A group of pupils come to the Trinity Lavra of St. Sergius. George, called Professor, Dimitry and his sister Anastasia sneak off the excursion quietly and go on their own to explore the mysterious corners of the monastery in the hope of finding treasures. The ancient staircase of the Duck Tower leads them to a secret chamber. On opening the door, the children come into the Forest of Wonder, where they meet Mongol warriors. The characters have to flee. Soon the guys realize that they are in the past. How can the children get back home? Just a miracle can help them. The children go to the Trinity Monastery through the mysterious forest to seek help from the miracle worker St. Sergius of Radonezh. Before they get there, the guys have to go through many adventures and challenges which help the kids to develop new qualities in themselves and find the right path.
Dimitry Druzhinin (12 years old)The boy is strong, sharp, dexterous and self-confident. He is a born leader and tries to keep the style of a "tough guy" and group leader. The boy has a noble heart, he cannot leave a man in trouble.
George Ezhov, called Professor (12 years old)He is Dima's classmate. The boy is smart, a kind of literate geek. George is unconfident, a bit coward and indecisive. He is afraid to take responsibility, so he often obeys a more strong-willed person. George dreams to be famous as a discoverer, fancies an academic degree and treasures, besides he is fond of eating.
Anastasia Druzhinina (12 years old)The girl is Dima's sister. She is obsessed with fashion, the way she looks bothers her all the time. The girl adores outfits and vibrant cover, ranging from nail polish to musicians. Anastasia is naughty and coquettish, at the same time she is kind and sensitive.
Bo'orchu (13 years old)The boy is khan's son. He is a clumsy guy. Bo'orchu is not a warrior at heart, but a romantic. He is interested in religion and science, not in archery or horseback riding. The guy is a little shy. Brothers consider Bo'orchu an oaf and laugh at him, but the guy is not a coward, the matter is cruelty contradicts his nature.
Andrei (10 years old)The orphan belongs to the gone days. Andrei is open-minded, calm, reasonable and mysterious. He seems to know everything in advance; it is not an accident that he comes to the Forest of Wonder to guide the guys and help them lead their way.
Sergius of Radonezh (40 years old)The Saint is a wise miracle worker, the greatest ascetic of the Russian land, the founder of the Holy Trinity Monastery near Moscow, now it is called the Trinity Lavra of St. Sergius. The Saint guides the children towards the Light and self-awareness, appearing when he is needed utmost.