The Pretender (S03E10)

King John has annulled his marriage to Queen Hadwisa to marry a 12-year-old French princess, Isabella. Furious, Hadwisa seeks revenge, plotting Isabella's assassination during a pilgrimage and framing Robin Hood for the crime. Meanwhile, Hadwisa's family believes they have the barons' backing to dethrone King John in favor of a young man claiming to be Arthur of Brittany, John's nephew. As Arthur secretly joins Robin's band, Gisburne seizes the opportunity to enhance his own standing and eliminate Robin. The Sheriff, aware that Isabella's demise would lead to dire consequences for all, finds himself incapacitated by a dog bite, unable to intervene.