Cas the Carpenter, with the help of Hernia the Helper, is asked to build a very cool hideaway fort under the dome of branches formed by a big, old weeping willow tree in the big backyard of Mr. & Mrs. Bigland for their son, Little Bert.Does Cas measure up to the task at hand? Can he really build a top-secret, not so big, fort hidden in the big weeping willow tree in the big yard for the not so big, Little Bert? It is a big job... can Cas do it?