The Sheriff, Gisbourne and Marian arrive in the Holy Land to put the deadly Shah Mat operation into action. The Sheriff and Gisborne meet their Saracen allies: a mercenary thug, Karim, and a twisted schemer, Nasir, who is to masquerade as Saladin's messenger and convince King Richard that Saladin wants peace.
Robin and the outlaws arrive, together at last, and bump into Carter, an old friend (from the episode "Get Carter"). Robin discovers the whereabouts of the King and sets off to find his old friend and hero. However, primed by the weasel Nasir, who has supplied him with false information (courtesy of the Sheriff) the King concludes that the man who intends to take his life is in fact Robin. It's a devastating blow, but in gratitude for saving the King's life in the past, Richard doesn't execute the outlaws but instead ties them up in the scorching desert, to live or die as fate decrees. The King then leaves for a peace talk with Saladin at a ruined town nearby: in truth, it is where the Sheriff plans to ambush and assassinate him.
A little while later the Sheriff turns up with a captive Marian and another Black Knight (who had previously appeared in the episode "A Clue: No"). They tie Marian up to Robin, delightedly taunt the gang on their failure, and leave to kill the King.
Fearing this may be their last chance, Robin and Marian begin to exchange wedding vows. Much cries at the moving service but there's jubilation when Carter appears on the horizon to rescue them, saying Much isn't crying, he's "laughing on the wrong side of his face".
The deadly meeting between the King and Saladin takes place. Nasir rides out and reveals his true and treacherous identity to King Richard. However, Nasir doesn't bargain on meeting Robin, who's taken the King's place. Their cover blown, the Sheriff and his allies retreat to the town and a furious battle to the death breaks out.
The band of heroes fight to save the king as they find themselves trapped by the Sheriff and his minions. King Richard saves Robin from Karim, and Robin retaliates by killing Nasir: however, Carter is slain by the Sheriff. The Sheriff sees a golden opportunity and fires an arrow into King Richard's back, snidely taunting "Long live the King!" Though his shot doesn't kill Richard, he is left severely injured, with Gisborne bearing down on the King, ready to finish him off.
Marian grabs Guy's attention by running out in front of him. An adamant Guy still wishes to escape back to England and take Marian for his bride, but his feelings are soon quashed when Marian tells him of her love for Robin. Unable to accept this, Guy runs Marian through with his sword just as Robin and his men arrive. Realizing what he's done, Guy backs away, looking guilty and afraid. The Sheriff flees on horseback, and Guy escapes with him, the Sheriff screaming at Robin that "This is not over, Hood!". As the group rush to aid the dying Marian, Robin kneels by her. Djaq explains that there is no hope of saving her: Gisbourne's sword is the only thing holding her broken body together. On hearing this, Marian rips the sword from her body, and she and Robin are finally married before she dies.
After the burials of Carter and Marian, King Richard tells Robin of their next move and proclaims with his men, "We are Robin Hood!" Djaq and Will reveal that they have decided to stay in the Holy Land together. The four remaining outlaws then begin their way home, ready to deal with the Sheriff and Gisbourne once and for all.