9. Lying To & Endangering His Companions To The Daleks
In the very next story, the Doctor recklessly endangers the lives of his companions by demanding that they enter the Dalek city in search of replacement mercury for the TARDIS fluid links which supply power to the ship. This exposes them to massive levels of radiation and later capture by the hostile Daleks. The Doctor then grudgingly is forced to admit that the fluid link excuse was a lie he concocted like a petulant child, purely because he wanted to explore the city. This story is the beginning of the attempt to soften the sharp edges of the Doctor character as he expresses regret at his reckless behavior, telling his companions he's "desperately sorry" for getting them into this mess, but for the first half he's still an unpleasant, grouchy old jerk. It's not too hard to imagine him yelling at Ian and Barbara to get off his lawn.