: Shipwrecked people accidentally end up on a populated island made up of shipwrecked ships where extraordinary adventures await them.
The big transatlantic liner Benjamin Franklin leaves from Genoa to New York. On board is detective Jim Simpkins, who is sending Reginald Gatling, suspected of murder, to America. In the open ocean, the ship crashes. Simpkins and Gatling do not have time to evacuate and remain on it together with the daughter of billionaire Miss Viviana Kingman who they saved. The ocean current nails a damaged liner to an unknown island in the Sargasso Sea, formed from the remains of ships of all kinds brought here for many centuries.
The island is home to several dozen people who came here after a shipwreck. The island is run by Fergus Slayton - a very dark person. At first, Slayton politely accepts new arrivals, but soon insists on Viviana becoming his wife, which causes her resistance. To avoid a scandal, Fergus announces that an equal “groom choice” will be arranged for Viviana. Fearing that Viviana will choose Gatling, Slayton orders his subordinates to put Simpkins and Gatling under lock and key. The ceremony begins.Before the Viviana pass all the men of the island, she rejects them. Slayton announces that Viviana will be his wife, and let the dissent try to measure his strength. Meanwhile, Gatling's sympathetic islander Ternip helps him and Simpkins get out of the cell. Gatling runs to the ceremony venue and defeats Slayton in a duel.
To avoid Slayton's revenge, Gatling with several inhabitants decides to repair the German submarine and escape from the island. On the night that everything is ready, they are noticed by Slayton's subordinates, and the conspirators decide to flee immediately. They chase. Gatling is wounded, but a bullet also hits Slayton. Everyone manages to board a submarine and set sail. Soon the ship picks them up.
On the steamboat, Simpkins learns from the newspaper that the crime that Gatling was charged with is solved, and the real criminal is punished. After arriving in the United States, Reginald and Viviana become husband and wife. They are interested in the Sargasso Sea, and they intend to explore it and visit on the way the Island of the Dead of Ships. Simpkins joins them to find documents on the island "explaining the secret of Slayton's fate." After a difficult voyage on the ship “Defiant”, travelers sail to the island.
When Gatling escaped with the company, Slayton was injured and his rival Flores became governor. The dying Slayton is forgotten. Flores orders to build bridges to the small "New Island" from the remains of the ships to solve the problem of housing and food.The islanders meet on the "New Island" Slayton, who survived, as well as a feral stranger. Slayton put under arrest. Flores wants to kill him at night, but Slayton manages to free himself from the cell, drive Flores there and seize power again.
At this time, the Caller approaches the island. The ship is assisted by the governor of the island of Bokko and tells travelers about the situation. They threaten to shell the island with guns if they are not allowed to land. Bocco promises to help and successfully persuades the islanders to overthrow Slayton. Slayton runs away. Flores is freed.
Simpkins finds documents that show that the feral inhabitant of the New Island is Slayton's younger brother, a talented pianist Edward Gortwan (Slayton was actually Abraham Gortwan). In order to take possession of Edward's huge fortune, Abraham put him in a psychiatric clinic, bribing some of the Montreal officials, where he lived. Fearing that with the advent of new people to the city administration, his scam would open, Abraham decided to take Edward to the Canary Islands. A strong storm overtook them along the way, the ship sank, and they reached the New Island on a boat. The night after arrival, Abraham moved to the Big Island, leaving Edward to his fate. Edward was very wild, but in the company of people, glimpses of his mind gradually began to appear.
While the expedition is exploring the island and its underwater world, Simpkins discovers that Slayton is hiding on a sailboat along with Chinese addicted to opium smoking, Hao-Jen. During the siege of the sailboat, a Chinese man blows up one of the ships. Oil from its tanks ignites, and a fire spreads across the Island.Residents of the island and members of the expedition sail away on the "Defiant".
