You are mistaken. It is a Mark III Travel Machine.
After starring in nine stories over eleven seasons, the Daleks had worn their narrative carpet a little threadbare. It’s hard keep your reputation as the supreme intergalactic conquerers when you’re invariably defeated time and again by a do-gooder with a blue box and a pocket full of trinkets; and harder still to remain interesting when your vocabulary doesn’t stretch much beyond “exterminate” and its various cognates. Efforts were made in the Pertwee era to imbue the Daleks with some degree of nuance and personality, giving them a thin range of emotions stretching from pride through to fear, but in the end, they remained much as the First Doctor found them in 1963.
To polish up the pepperpots for a new generation, Terry Nation’s “Genesis of the Daleks” (Story Production Code 4E) sends the Fourth Doctor, Sarah, and Harry back in time, before the events of “The Daleks,” to the moment of the Daleks’ creation. While the show has revisited plots and villains before, this story marks the first instance of Doctor Who really mining its own history as the basis for a story, as well as representing one of the show’s few actual uses of the time travel conceit as something other than an easy means of changing the stage setting. Does one dare change the future by altering the past?
The Time Lords snatch our beleaguered time travellers straight out of the transmat beam to Space Station Nerva, not even giving them a chance to change clothes after the last story before sending them back in time to Skaro, sans TARDIS. The Doctor’s mission, should he choose to accept it, is nothing less than the prevention of the Dalek threat before it has a chance to develop. Though they leave the means up to the Doctor, the Time Lords make clear that they will countenance any actions he might take in pursuit of this end. A far cry, indeed, from the Time Lords who banished the Second Doctor for his continued interference in the affairs of the universe, though charitably one can assume that his excoriation of their indifference to evil helped soften their resolve.
The Doctor sees wisdom in the idea of intervening in the Daleks’ creation, possibly by nudging their development towards less aggressive tendencies or by learning some weakness in their essential nature that will allow future generations to defeat them. And yet, in the end, the more intricate and less violent options fall by the wayside, leaving the Doctor with the simple choice: touch two wires together to blow up a nursery of tiny Daleks or allow them to take over the galaxy…