The last days of 1933. After the failed attempt to assassinate King Alexander in Zagreb, it is clear that Yugoslavia is in a serious political crisis. Great political and strategic games are entangled both domestically and abroad, the very survival of Yugoslavia is called into question. However, Belgrade is shaken by something completely different; a gruesome murder on Avala, in the medieval fortress of Žrnov at the place where a monument to the unknown hero Ivan Meštrović will soon be built. Inspector Pletikosić, the current head of the Belgrade Department for Blood and Sexual Crimes, takes over the investigation, with the help of his young assistant Zečević.
After the arrest of the insane Rajko, an order comes from the highest institutions to stop the investigation of the murder in Žrnovo. Inspector Pletikosić, doubting this theory, asks for help from his friend and former boss, Inspector Tanasijević, who, having left the police, now leads a completely different life.
The killer's trail leads to the grave of the unknown hero and the secret of who is really buried there. But while investigating that clue, Stanko and Zečević, with the help of Tane, come across clues that spread the mystery even more. Meanwhile, in Italy, right on the border with Yugoslavia, a new "strong" man of the underworld is preparing to enter the scene. Tomasović rescues the Macedonian terrorist Damjan from his Ustasha friends yesterday, and through him he wants to establish the Yugoslav production and distribution of a new drug - heroin. Fortunately, Maja Davidović and Mustafa Golubić, although ideological enemies, decide to cooperate in discovering who is behind the plot to kill the king.
A huge scandal erupts with the discovery of Count Novicki's corpse. Maja asks Tane for help in the investigation that she is conducting herself. The plan to demolish Jatagan Mala and build a new settlement in its place is starting to be realized. Mirić receives instructions to cooperate with Godina, a mole in the Ustasha ranks, in the opium trade. Obrad Savković, the owner of the magazine "Novog doba", implements his agenda step by step using intrigues and blackmail. Maja gets more and more entangled in a story she doesn't fully understand. Tomasović approaches Mirić in order to agree on cooperation. Sonja, Tane's ex-wife, leaves her husband.