FULL EPISODE SYNOPSIS (spoiler!)
Several months have passed, when a pirate ship approaches the island one day. Ben is the first to see it. When Parsons looks at the ship through the telescope he recognises its name. It's the Viper. On board serves one of his mates, a young man called Joseph Creel.
The Robinsons have managed to plant a garden and can expect a rich harvest, even some wheat. For this David is building a mill. Ernst declares that in two days it will be the 4th of July - Independence Day. This news excites the family and they plan to have a celebration on that day. For the occasion Ernst and Billy go hunting. They are watched by Parsons and Ben who have once again come over to the island.
The pirates drop anchor and row ashore. They need fresh water and supplies. Joseph Creel hides a coffer full of gold coins in one of the empty water barrels and carries it to shore. Captain Samuel Scaggs and his mistress Bonnie Mary get suspicious when they see him struggling so hard with the presumedly empty water barrel. They follow him, along with some of the other pirates and catch him digging a hole in the sand.
Billy discovers the ship and alerts Ernst to it. They run towards it. On the beach they discover the crew and approach them. Quickly Billy realises who they are dealing with. He and Ernst follow Scaggs's invitation to come aboard the Viper. Billy claims that only he, Ernst and their dog Bruno are living on the island. Scaggs and Bonnie Mary are not entirely convinced however. The boys are forced to watch how Joseph Creel must walk the plank and gets devoured by a shark. Next, Scaggs forces Ernst onto the plank. But the young Robinson remains steadfast and does not change his statement about nobody else being on the island. Eventually Bonnie Mary intervenes and prevents Ernst from sharing Creel's fate. Instead Ernst is to work as cabin boy for Scaggs. For now, however, the boys are chained below deck.
Meanwhile Parsons and Ben have also been discovered by two of the pirates and are brought before Scaggs and Bonny Mary. The Captain recognises Parsons who is willing to share a secret with him.
Bruno has run back to the treehouse. The family is alarmed and David follows Bruno to look for the missing boys. At nightfall he returns without having found them.
During the night the pirates sail around the island, drop anchor near the treehouse and invade it. Ernst hears Christina's scream and is frustrated with his helplessness. Again he pulls at his chains as he has done before, but still to no avail. Parsons visits Ernst in his hold and tells him that Scaggs will hang his father the following morning. Ernst tries to attack Parsons but his chains prevent him from doing the man harm.
Scaggs and Mary claim the parent's bedroom for themselves and put David and Elisabeth in one room with Christina, Joanna, Emily and Billy. The guard in front of their room doses off. David sneaks outside and tries to take the man's gun but is discovered by Scaggs.
The next morning Ernst and Billy are still pulling hard at their chains, hoping to loosen the bolt that holds them to the mast. Ben visits them. He feels sorry to be unable to help them escape, however, he would be willing to put in a good word for Billy. Billy eagerly accepts the offer. After Ben has gone, Billy turns to Ernst and tells him that when he is free he might be able to do something for the family.
Scaggs is willing to take Billy on his crew. To make him prove his loyalty and to humiliate the Robinsons, Billy is made to wear fine clothes and has to let the Robinsons serve him lunch. Billy is very uncomfortable with this, but David and Elisabeth support him as they know that Billy has no choice but to do what is asked of him.
Emily manages to convince Scaggs and Mary that she is a valuable hostage and that her father as well as her fiancé would pay a king's ransom for her safe return.
Finally Ernst manages to pull the bolt from the wood. He calls for water and when a pirate appears he tricks and attacks him. When the pirate is knocked out Ernst takes the key for the chains and frees himself. But the pirate is a tough man and recovers swiftly. He attacks Ernst with a knife when he tries to leave the cabin and cuts him at the side. Still, Ernst manages to knock the pirate down again, slip over the side unnoticed and swim to shore. Having reached the edge of the forest he drops to the ground exhausted and loses consciousness. After a while he is found by Bruno who helps him evade the pirates that have come looking for Ernst by now.
Elisabeth also tries telling Scaggs that he would be richly rewarded by her father if he returned them to Boston safely. Scaggs, though, has something else on his mind. He fancies Elisabeth, much to the displeasure of Bonnie Mary.
On Parsons accusation Scaggs puts David on trial for the murder of Seth Parsons. Scaggs takes position as the judge. David refuses to take part in this travesty and his daughters proclaim his innocence. Suddenly Ernst appears with a loaded pistol and points it at Scaggs demanding his family's release. But he is weak and quickly overcome by some of the pirates.
While Ernst retires to his hammock where he is tended by his mother and sisters, the pirates build a gallows. When the time of the execution has come Elisabeth pleads for her husband's life. She offers Scaggs to farm and raise animals for him, to give him a regular base to come back to. Bonnie Mary and Scaggs like the idea and spare David.
But then Scaggs discovers that the family was planning to celebrate the 4th of July. Even though he is a criminal he still sees himself as a loyal servant of the British Empire and therefore despises the Americans. He wants the whole family to swear an oath on the bible and renounce their country. But none of them will. Enraged, Scaggs plans to murder the entire family and leave Parsons and Ben and Billy behind to farm and raise animals for them.
Billy, however, has a clever idea. He goes to Emily and enlists her help. She stumbles out of her room, her face covered with black marks, pretending to have the small pocks. The pirates fear the illness and run for the lives. So do Parsons and Ben. When they have gone Emily and Billy tell the family that it was a trick. They are relieved and happy. Together they celebrate their independence on Independence Day - thanks to Billy.
© Cloud 9 Screen Entertainment & CLT-UFA International