This is the seventh book in the “Emerald City” series by Sergei Sukhinov. The sorcerer Pakir does not give up trying to escape from the dungeon where the wizard Thorn imprisoned him. At the military council of the Magic Land, a decision is made to attack the enemy in his lair. The fleet of the Army of Light is sent to the Underground Country. But the journey to the Kingdom of Darkness was not easy. The Army of Light is opposed by monstrous monsters, and they have to rely only on their own strength - after all, the Guardian of the Thorn Ellie fell into a trap set by the treacherous princess Langa.