Tuffnut breaks his beloved mace trying to break the Hunters's dragon proof chains, and Tuffnut states it is in desperate need for repairs. First, he goes to Hiccup and asks to fix his beloved mace but then Hiccup refuses and says he can't, and that they might as well go back to Berk and let Gobber fix it, but Ruffnut and Tuffnut weren't going back there so the Twins go to the Hunter-swarmed Northern Markets to replace it. Using their 'twintuition,' the Twins follow the repaired and stolen Macey to find a hidden Hunter operation called 'Project Shellfire.' Tuffnut, who deeply cares for his mace, tries to take it back on his own, while Ruffnut is captured by Viggo and Ryker to be used as bait for a trap for the others. Tuffnut learns to put the needs of the team before his own and saves the others by sacrificing his Macey and freeing the others. The Twins hold a funeral for Macey back on the Edge, where Tuffnut reveals stolen schematics that leave the Riders worried for what 'Project Shellfire' entails.
Macey is destroyed and the twins give her a Viking funeral.
When Ruff takes off the Hunter helmet to talk to Tuff, her small side braids are gone. They're still gone when Ryker figures out who she is and takes her helmet off. But suddenly when she's in Viggo's quartets, the braids are back.
Tuffnut's line, "I have two favorite things! Yak jerky and kicking butt! And I don't have any yak jerky on me!", is a direct reference to Roddy Piper's improvised line in the film They Live.
Fishlegs takes a deep breath and holds it when he goes to pull Ruffnut out of the water but his head never actually enters the water.