From inside the control room of his TARDIS, the First Doctor tells a new companion that if they are determined to keep on travelling with him, then they must know exactly what to do if they face the Pyromeths. This speech is continued throughout the Doctor's lives, as the Second Doctor describes them to Jamie McCrimmon as "hideous" and having existed since the dawn of time, while the Third Doctor tells a disbelieving Jo Grant that they are even older than the Time Lords. The Fourth Doctor explains to Leela that they gave the gift of fire to every race in the universe, but the Fifth Doctor clarifies to Nyssa that it was not to cook or keep warm - the Sixth Doctor tells Frobisher that it was to tell stories around, as they feed on psychic energy from imagination. The Seventh Doctor warns Ace that she must keep her guard up, as the Eighth Doctor tells Molly O'Sullivan that she would be snatched away to a secret location, telling tales forever. The Ninth Doctor warns Rose Tyler that if she stops, then she will be extinguished like the fire they grant, and urges her to remember one thing. Finally, sitting in the TARDIS with the Tenth Doctor, Martha Jones asks what that one thing is, but the Doctor changes the subject as they have just landed at a new destination.