The Daleks had been defeated, but at a terrible price. Thanks to the Time Destructor, the once fertile world of Kembel had been reduced to a barren desert. The Doctor knew it would take centuries for the planet to recover - if it ever did. But, more than that, he had seen two of his own companions die during this adventure; two young women, born centuries apart, had fallen in the fight to stop the Daleks' latest plot to conquer the Universe. He hadn't known either of them for very long, but that did nothing to lessen the sense of loss.
Loss. The Doctor had some experience of that already, having seen first Susan, then Ian and Barbara, then Vicki leave the TARDIS. But Katarina, the Trojan handmaiden, had been the first of his companions to die. An escaped convict who had stowed away on the spacecraft the Doctor and his companions were travelling in had taken her hostage; to keep him from forcing the craft to head back to Kembel, she had opened the airlock and jettisoned her captor. Sadly, she had also jettisoned herself and her body was now floating in the vacuum of space.
With the threat of the Daleks still present, the Doctor and Steven had had little time to mourn Katarina's death. The main priority had been keeping the Daleks from regaining possession of the Time Destructor's core (made from the rare mineral taranium) which the Doctor had stolen. In the end, after a long chase through time and space, the Doctor had been forced to hand the core over. All had seemed lost - until he turned the Time Destructor against the Daleks. Time on Kembel had begun racing forwards, causing all living things on the planet to wither and die, including his newest companion, Sara Kingdom.
The Doctor shook his head, recalling how, when he and Steven first met Sara, she had been trying to kill them; she had already killed their friend, Bret Vyon, who had turned out to be her brother. In the end, however, she had given her life to make sure the Doctor made it back to the TARDIS safely. Her death had been more horrific than Katarina's; the Time Destructor had aged her to death, then accelerated her body's decomposition until she was nothing but dust.
The Doctor glanced across at Steven, who was looking down at the TARDIS console with unfocused eyes. There was no need to ask; it was obvious that Steven's mind was preoccupied with memories of Katarina and Sara. Nevertheless, the Doctor broke the sombre silence with the words: "You miss them, don't you?"
Steven nodded, not trusting himself to speak. The deaths of both women played over and over in his mind, as if on an endless loop. Katarina, struggling and crying in the airlock, then floating lifeless in space. Sara, reduced to a wizened crone, collapsing in the dust yards from the TARDIS . . . Steven suddenly became aware of a burning sensation in his eyes.
"As do I, my boy," the Doctor said. "But they gave their lives to save us and we must take comfort in that. Yes, we must take comfort in that."
All the same, this had been a Pyrrhic victory; the deaths of two companions had been a heavy price to pay. Would Katarina and Sara be the only ones? Or were there others, scattered through time and space, who were destined to meet a similar fate? The Doctor had no way of knowing, but he knew one thing; right now, he wanted to get as far away from the planet Kembel as possible.
Without saying another word, he pressed the dematerialisation switch and, with its characteristic sound, the TARDIS slowly faded away, leaving behind a devastated planet. The result of the terrible power of the Time Destructor . . . All the Doctor could do now was hope it would be a long time before the Daleks attempted anything on this scale again.
But, after four encounters with the Daleks, he knew they would never give up their desire for conquest.