While playing on a home made flying fox, Lou gets a hard bump on the head when she collides with a young girl who seemingly ignored Jerry's warning and ran into Lou's path. The young girl runs off, and in a half daze, Lou thinks that she has seen an almost extinct wallaby in the bush. None else saw the wallaby. They find out that the mysterious girl in is the daughter of the visiting researcher, also that she is deaf. The kids quickly make friends with Bridget and enjoy learning sign language. While there is some doubt that Lou really saw the wallaby, the adults decide to look just in case. After upsetting their search , Lou, Bridget and Jerry go off on their own, and Lou gets into trouble, eventually needed to be rescued by Ranger Dave and the helicopter. In the end, Lou and Skippy are the only ones who know for certain that the wallaby was really there!