The US Air Force and air traffic control seek FBI help when a UFO flying over LA seems a possible terrorist threat. Charlie finds mathematical ways to combine and filter radar observations to identify routes and craft type. It's a flying wing design, like aeronautic engineer David Croft and his former partner Gosnell invented. Don tracks down the last, who indeed build one with his son Blake and Paul Ridenhauer's German venture capital fund as investor, but is missing. Inspired by chaos in golf, which he plays to please dad, Charlie helps figure out where to, thus discovering a killing.