Alderjack is a golden-furred squirrel that is Abbey Warrior, long-time resident of Mossflower Woods, and main protagonist of Siege over Mossflower Country. He was raised by Goodwife Nutbrush and became best friend and lifelong companion of her son, Treescamp. Though he could be serious and determined, Alderjack was normally very happy and joking. It was he and Treescamp who alerted the presence of Syzran to Abbot Arstead. Although he did not live at Redwall, he visited occasionally, but that did not stop him from having a connection with the ancient Abbey. After failing to catch the Wisp, who stole the Sword of Martin, three dibbuns, and the Tapestry, he was dejected and was determined to retrieve it. That night, the young squirrel was visited in a dream by Martin the Warrior, telling him to retrieve the dibbuns, the tapestry, and Martin's sword. After meeting a jovial young hare named Horlington Bradshaw Vittlescoff III, he, Treescamp, and their new friend went questing to find Redwall's stolen treasures. Joined by a young ottermaid named Slimbrook, they came across many obstacles, including Flitchaye, Toads, Adders, rough waters, and quicksand. Finally, when they got to the camp, they easily gained the dibbuns back, only realizing that they were trapped by Syzran's Horde. They were then rescued by Laird Rockwing, an owl friend Alderjack had saved earlier, and a troop of Guosim shrews. Alderjack, his friends, and the Guosim flew back to Redwall on the backs of the huge owl and his sons. At Redwall, the Redwallers thought the attack was over until Syzran himself arrived. During the huge war, Alderjack dueled with Syzran and beheaded him. With Redwall victorious, The Redwallers and their allies finished the delayed Jubilee Feast and Alderjack officially becomes Abbey Warrior.