First thing in the morning, when brother and sister go outside to enjoy the winter weather, Martin heads straight to the old oak tree to "check on it." Sylvia is curious — what is Martin doing? Martin explains that he learned what it is to be a "tree keeper" at his wilderness school. He has chosen the oak tree to be his tree to watch over. Sylvia begins the search for her own tree and finds that the perfect tree to "keep" is not at all what she expected.