After the defeat of the September Uprising in 1923, a group of rebels are detained on an island in the Black Sea, while awaiting their sentences. Kosta Rika, an old salt, is planning an escape. The carpenter Zheko,the Student and the Doctor find out about it. In the preparation the Student unwittingly caused Kosta Rika's death. Although not under the death sentence, the romantic young man decides to swim to the shore and organize the escape of the others, but dies. Zheko tries to make use of the target practice rafts, but is shot dead like a human target. After the death of the three the Doctor organize a mass escape. He menages to obtain permission to show a theatrical play to prisoners. During the performance the prisoners take the guards by surprise and disarm them all, including the brutal Captain Stanev. He attempts by force to prevent the lighthouse keeper from switching on the light as this is the only way to warn those on shore that something is wrong on the island. With the help of the lighthouse keeper's little daughter the Doctor succeeds in reaching the lighthouse and turning the light on. The prisoners get in boat to sail to the shore. On the way the Dctor slips and breaks his leg. He decides that he must not hinder the escape of his comrades, bids farewell to them and to his little helper, and blows himself up.