A 17th-century aristocratic plan that went awry and the secret of the Roman occupation await Aubrey Manning when he visits the Fens in East Anglia. In pursuit of the last remaining piece of undrained fen, the retired professor uncovers a lost way of life from the middle ages plus hidden prehistoric hills. Is this flat, drained farmland really completely man-made?
Director John Triffitt ; Executive producer Richard Reisz (S) (W)