This season aired between 1st September 1979 to 12th Januraray 1980. It featured The 4th Doctor with Romana and K9. The main enemies/aliens are The Daleks, Davros, The Movellans, Scaroth, Lady Adrasta, Mandrels, Tryst and The Nimon. The episodes are:
105. City of Death
106. The Creature From the Pit
107. Nightmare of Eden
108. The Horns of Nimon
Un-Broadcast episode. Shada