A village on the outskirts of Sherwood Forest is regularly raided by a horde of Mongols. Robin and his band rescue a maiden from the village who has been kidnapped, angering the Mongols. The village elders refuse Robin's help in fighting back against them, fearing too much bloodshed, but the younger citizens are prepared to fight for their freedom.

A band of Vikings capture Prince John, to hold him for ransom, and Robin, who is out hunting with Little John. Robin and his men enable Prince John's escape, but will he live up to his promise to pardon Robin and his men?

On Prince John's orders, Captain Delouche, an evil knight armed with magic, impenetrable armor, rounds up many young women from the Sherwood Forest area for a beauty contest, with marriage to Delouche for the winner and a sacrificial death for the loser. The abducted women include Little John's sister, Natalie. The magic armor can only be defeated by the Golden Arrow, which Robin has to take from Prince John's castle, and use against Delouche, to rescue the maidens.

The Saxon Lord Sedgewick owes a large amount in taxes to Prince John, and if he doesn't pay, his granddaughter, Lady Pamela, will have to marry Sir Gilbert. So she requests Robin's help. Robin enters a contest, The Race Against Death, devised by Prince John, with a huge sum of money as prize, but finds it is rigged against him. Robin ends up needing to be rescued by his men from inside the castle.

Marion sets out to save her young cousin, Iris, from a marriage arranged by her evil sister-in-law, Lady Isabelle, to Lord Garth. Isabelle has told Iris that her intended, Thomas of Glockshire, was killed in the crusades, but he is actually on his way back. He meets Robin and his men, who are on their way to help Marion. Marion saves Iris, and returns to Sherwood, only to find that Robin and his men are now catives in Isabelle's castle, and Marion must now return there to rescue them.

Robin meets a young boy, Patrick, who leads a group of orphans on the run from Prince John's soldiers. On taking the boy back to camp he discovers that he is a real hand full. The boy knocks Robin unconscious, and escapes to reassemble his group in the woods. While unconscious, Robin recalls his encounter with the magician, Olwyn. He was then about the same age as Patrick, and also running for his life in the forest from the men who killed his father, the Earl of Locksley, and sacked their home, leaving Robin a penniless orphan. Olwyn offered Robin refuge, and told him he was the chosen one. Friar Tuck convinces Patrick to give all his booty to Robin's cause.

Three beautiful, evil witches take Little John captive, and make him their slave. Robin's band cannot breech the catacombs of the abbey where the witches have taken him, because of the powerful magic they practise. Robin uses a magic potion from Friar Tuck to fake his own death, knowing that his evil Aunt Alice, the Abbess, will entomb him in the family crypt inside the abbey. He thus gains entry to rescue Little John and vanquish the witches.

An evil warrior from the Middle East seeks to make Marion part of his harem.

Robin goes to the fiftieth birthday party of his step-mother, where he encounters an old girlfriend. But a band of thieves enter the castle and interrupt the festivities. They round up the guests and steal all their money and trinkets. Robin is seriously wounded in the battle to recover the stolen items. Knowing the castle well, he relies on his cunning to separate the thieves, and lay traps for them in the rooms they find themselves locked in. But Robin faces his biggest battle high on the castle walls.

The God of Healers sent her young daughter, Gwyneth, from Avalon to live amongst mortals many years ago. The beautiful young healer must return home before her twenty-first birthday, or all who have been healed by her hand will die. Unknown to Robin, he was her first healing when he hit his head as a child, an act that was witnessed by his sworn enemy, Sir Guy of Gisborne. Sir Guy, knowing the consequences if she does not make it home, enlists the help of the evil witch Mordrelle, who was banished from Avalon many years ago, to help prevent Gwyneth's return. But Sir Guy is killed in a fight with Robin, and brought back to life by Gwyneth, so putting him in the same position as Robin. Sir Guy has to kill Mordrelle to enable Gwyneth's return to Avalon.

Marion sees a giant fireball fall from the sky into Sherwood Forest, and rushes off in search of what it has brought. When she reaches the site, she discovers a strange, diamond-encrusted creature. She befriends him, and tries to help him discover what he needs to return home. Lady Claudia has also seen the fireball and sends Barkley to follow its path, and gather the untold riches that she believes it is supposed to provide. When Marion does not return to camp, Robin sets out to find her. Then he and Marion must fight to save the creature from the grasp of Lady Claudia's men, and help it return to its ship.

A mysterious black castle, occupied by an evil creature, has the power to wreak havoc on the world and destroy it. Olwyn, the ancient magician, tells Robin he must discover the architecture of the old castle and learn its secrets in order to kill the creature and nullify the castle's powers. But first Robin has to rescue the family of the Engineer, who are being held captive inside.