Two men exhausted by the strain, their clothes in tatters, are getting close to the Thunderbolt, a ship helmed by the Black Corsair. Carmaux and Van Stiller, are buccaneers that managed to escape death by hanging after sailing on the ship of the Red Corsair, the Black Corsair's brother.

On the Spanish ship that has just been conquered, the Black Corsair interrogates the prisoner and discovers that she is a duchess, Honorata Willerman duchess of Weltendrem. The Black Corsair decides to take her to Tortuga, so as to let his men ask for a large ransom in exchange for her release.

When they arrive at Tortuga, the Black Corsair informs Honorata that she is free: he has paid the ransom. Surprisingly, she goes to the house of the Black Corsair. In the meantime, the Olonois informs the him that it has been decided by all pirates to launch a great attack on Maracaibo.

The Black Corsair leads the powerful fleet towards Maracaibo, where Van Gould is expecting him. They then meet two Spanish warships. After both ships are conquered, the Black Corsair finds the Duchess waiting for him. When he says the name of his enemy, Van Gould, the duchess faints.

While the Corsair ships attack Maracaibo, bombarding it with gunfire, the pirates, armed to their teeth, reach the beach on the lifeboats. The battle is terrible, and the town falls only after a brave resistance.

The trek is long and wrought with danger. Food is scarce and in addition to the threat of fierce animals, there are also terrible cannibal natives, who are determined to eliminate the intruders in what ever way suits them best. Carmaux, in an attempt to get some food, runs into thousands of mishaps.

As they arrive at the bay, the Black Corsair and his friends see Van Gould together with three other men on a lifeboat that has just set off. They chase them on another boat, but just when they are quite sure of capturing him, a Spanish ship bars their way and Van Gould takes refuge on board.

During the night, the Count of Lerna frees the Corsair and his friends, and with the help of the dark, they leave the ship on a life boat and rejoin the Corsair's fleet and head for Gibraltar.

A year has elapsed since the Black Corsair abandoned Honorata at sea, and remorse and regret have not given him any rest. On board his ship, the Thunderbolt, he goes to Puerto Limon, seat of a small Spanish garrison.

They are freed by Yara, who is herself a mortal enemy of Van Gould's. In their attempt to get out of the house surrounded by Spaniards, the Black Corsair is seriously injured, and carried back to Yara's abode, from where he and his friends desperately look for another way out.

Two Spanish frigates obstruct the exit of the bay and prevent the Thunderbolt from exiting the port. With an ingenious stratagem, which proves for time the valour of Carmaux, Van Stiller, Moko, Leila and their animals, the ship manages to get out, and Yara relates her sad story to the Black Corsair.

After innumerable adventures and vicissitudes, our friends reach Veracruz, where a messenger of the pirates of the Tortuga is expecting them. The attack to the town has had to be put forward, and they only have one night to find and kill Van Gould.

The buccaneers have attacked Veracruz, and the town has turned into a battlefield. The Black Corsair tells the other Corsairs that he wants to get into the fort by stealth, in order to speak to the man who has information on Honorata.

When, at the cost of huge losses, the other Corsairs manage to conquer the fort, they find out that the Black Corsair and friends have been captured and taken on board a Spanish ship, the Alhambra, which has already set sail for Cardenas, where the Corsair is going to be handed over to Van Gould.

Van Gould's powerful frigate reaches the Thunderbolt and while the hurricane is raging, the two enemies, in command of their ships, give do battle. The Black Corsair, heedless of the terrible storm and the gunfire from the Spanish ship, orders the boarding.

Hungry and thirsty, and with the prospect of having to face the terrible natives, our friends are on the coast of Florida, armed only with a knife and a dagger.

Afraid of being ambushed by the natives, they advance warily through the forest, but after some time, then feel the presence of the natives. They try to elude them, mostly by hiding, however, the first to be captured are Carmaux and Moko, who had strayed from the others in search of food.

During the night, they manage to untie themselves and run away, aiming to take some of the natives' canoes and paddles. While they are desperately paddling, the natives, having noticed their escape, then bar the exit of the bay on their other canoes.

They remain locked up in the cage for several days and nights, with nothing to do but look at their warders, who, armed with war clubs, never let them out of their sight. On the day appointed for the judgement, the Black Corsair sees in the distance the figure of a woman, who pointing to them proclaims them to be sacred and untouchable.

Carmaux, Van Stiller, Moko, and Leila have returned to Tortuga, thanks to some fishermen who picked them up, and they understand what has happened. They find out that Morgan managed to save the Thunderbolt, and though their hearts are filled with sorrow, they resume their life as buccaneers.

Crossing the forest, our buccaneers meet a boy, Moko, who had previously helped the two runaways leading them to a boat. Moko decides to join the Black Corsair in the adventure.

As the Black Corsair, Moko, Carmaux and Rum cross the little town of Maracaibo, they get to the square where the hanged men are, and decide to take away the body of the Red Corsair in the middle of the night. A bloody strife with the Basques follows.

By this time the town is in a state of alarm, and the presence of the buccaneers has been discovered. Moko and Van Stiller return to the town to look for the Black Corsair.

Having detained the Count of Lerna, the Black Corsair and his friends are barricaded inside the notary's house. The Spaniards have surrounded the house and it is only the pirates' threat of blowing up a small cask of dynamite that has prevented the Spaniards from attacking the house.

The group returns to the Thunderbolt, where they meet Morgan. The body of the Red Corsair is delivered to the sea, and during the ceremony, the Black Corsair swears he will kill Van Gould and exterminate his entire family. A Spanish ship is sighted, and the Thunderbolt prepares to attack it.

The duel between the two ships is long and exhausting, with many losses on both sides, but in the end, the Thunderbolt manages to ram the other ship. The pirates, led by the Black Corsair, go for the boarding, and after a furious hand to hand struggle, the last Spaniards surrender.