Disaster occurred in the Karsky family: Tomek’s cousin was arrested and exiled to Siberia. And in order to save him, Tomek, in the company of Vilmovsky Sr. and his faithful friends - the boatswain Novitsky and the trapper Jan Smuha - goes to Russia. The young man owes a lot to the Karskys, who, after the death of Tomek’s mother and his father’s escape abroad, replaced the boy’s parents. However, this time the expedition may cost the travelers their freedom and even their lives, because an agent of the tsarist police is assigned to them as an observer. Will the friends manage to free the exile and avoid falling into the clutches of the authorities themselves? Tomek's heart is full of doubts, but if there is even the slightest chance to save his brother, the brave young man will go to the end! More than one generation of young book lovers has grown up on the stories about the fearless Tomek Wilmovsky, which came from the pen of the Polish writer Alfred Shklyarsky. Here is the fifth novel from this series - “Tomek and the Mysterious Journey”, the translation of which has been re-verified and supplemented with interesting and informative popular science references. Wonderful illustrations for the book were created by the artist Vladimir Kanivets. The publishing design is preserved in PDF A4 format.