In the search for clues as to Chuck's disappearance, Captain Midnight and his friends investigate an isolated landing field. On it, is a shack, half hidden under the trees, where Captain Midnight and Fred Hilton go to investigate, whilst Patsy and Steve go to examine some aeroplane wheel tracks which had attracted their attention. Suddenly Patsy notices that Captain Midnight and Fred Hilton are waving at them to come to the shack...