"The Seeds of Death - Episode Six"

Doctor Who
Airdate: March 1, 1969
Patrick Troughton, Frazer Hines, Wendy Padbury
Written by Brian Hayles
Produced by Peter Bryant
Directed by Michael Ferguson

Jamie distracts the Warrior while Zoe lets the Doctor into the Weather Control Bureau. The Doctor rigs up a portable version of the solar energy weapon Phipps used on the moon and uses it to destroy the Warrior. He repairs the weather controls and arranges for it to start raining. Meanwhile, Miss Kelly and Prof. Eldred succeed in matching the Ice Warriors' radio signal and the satellite is launched. The Doctor T-Mats back to the moon with his device in order to knock out the real signal. Diverted by the false signal, the Ice Warrior fleet changes course. When the Doctor doesn't return, Jamie T-Mats back to the moon and rescues the Doctor from the remaining Warriors. While everyone is busy celebrating their victory, the Doctor and his friends slip quietly away back to the TARDIS...

The one major innovation in the Ice Warriors introduced with this story is the introduction of a caste system. All of the Ice Warriors we saw in their first appearance were typical soldiers. This story introduces an Ice Lord, Slaar. He is the leader, his costume is a bit different, and he seems to be somewhat more humanoid in appearance. Each subsequent appearance of the Ice Warriors will feature an Ice Lord. In fact, all three Ice Lords we will see in this series were played by the same actor, Alan Bennion.

By the time this story was transmitted, Patrick Troughton's decision to leave the series had already been announced to the general public. In a sense, this story is the final example of a certain type of adventure that typified Troughton's tenure. Neither of the next two stories feature any space monsters. In fact, all of the characters in the next story, "The Space Pirates", are human, and in Troughton's last story, "The War Games", the only aliens in it are entirely humanoid in appearance. Of course, this is far from the last time we'll see the Doctor battling space monsters, but it is the last time we'll see this Doctor battling space monsters.