Gisborne and Robin unite to save their half-brother, Archer, who is awaiting execution in York. But before long, old tensions resurface. Meanwhile, Isabella is paranoid that Gisborne and Robin are plotting against her, so she has her guard track them down.
Robin breaks into Isabella's chamber, hoping to strike a deal with the new sheriff. Later, her reign comes to an abrupt halt when her evil husband, Squire Thornton, arrives and announces he's taking over.
A heat wave hits Nottingham and Prince John decides to cut the water supply, sending the outlaws on a daring mission to retrieve water for the dehydrated villagers. Meanwhile, Robin and Isabella secretly meet.
Robin rescues a beautiful aristocrat (Lara Pulver) when sinister men try to chase her down in the forest, but she soon proves she's no pushover. Meanwhile, Gisborne returns from the court of Prince John with instructions to kill Robin Hood.