The Thals turn out to be pretty good guerrilla fighters against the Daleks once the Doctor shows up. Two Daleks get killed by the liquid ice explosion in their tunnel, two more are killed by the bomb, one falls all the way down the ventilator shaft, two get led into the ice pool on the surface, and two more are locked forever in the sealed germ lab with lethal bacteria. That seems to leave seven in this episode, so maybe sixteen on the planet in total. The Thals said that there were about a dozen Daleks here. They were off by four. Their hit and run tactics are better than their field intelligence, I guess.
In the best scene in this episode, the newly-arrived Dalek Supreme, represented by a refurbished prop from the two Dalek movies produced by Amicus in the 1960s, gets sick of one of the seven remaining Daleks’ failure and exterminates him. Our son, who really, really enjoyed all the last-minute escapes and explosions this time, had eyes like dinner plates. “Daleks killing other Daleks?!” he shouted, amazed. He was petrified by the bit where the Doctor has to drop down onto the floor of the Daleks’ refrigeration chamber and retrieve a bomb while groggy Daleks start emerging from hibernation and hid behind the sofa.
One other little moment of note: the show has told us that Jo has gone into space four times now: “Colony in Space,” “The Curse of Peladon,” “The Mutants,” and the arc of these last three stories. (Since she begins “Frontier” wearing the same outfit she wore in “Carnival,” and has Drashigs fresh on her mind, I suggest they didn’t go back to Earth between the two.) This is the second of her four trips away from our planet where she’s broken the heart of a space boyfriend. Fortunately, she looks pretty well done with space travel by the end of this one.
(Although, twelve years after this serial was made, a later TV adventure called “Timelash” would establish that this Doctor took Jo and an unnamed third traveling companion to the planet Karfel, the setting for that story. Ten years after “Timelash,” the author Paul Leonard wrote a pair of novels for Virgin Books that explained that little continuity blip, and showed that sometime after “Planet of the Daleks” but before the next adventure, the Doctor, Jo, and Captain Yates had some adventures together. I’ll only accept that as canon if Jo broke some other spaceman’s heart along the way.)