Trudy Morgan and her sister Olwen lived with their parents and grandfather on a farm near Cwm Llewellyn in the Welsh hills. One stormy night the two sisters discovered an ancient sword. It turned out to be the magic sword of Prince Llewellyn. The sword sang to give a warning when danger threatened the valley.
- The Legend of the Singing Sword – Mandy: #359 (1 December 1973) – #364 (5 January 1974)