Relative Dimensions starts by tying up a couple of loose ends. We see what Jackie has done with the money she got as part of Rose’s Betrothal ‘dowry’. A better lifestyle for herself, and a financial leg up for Mickey who moves out of the lock-up garage seen in Christmas Invasion to a new, smart premises. And those premises provide the backdrop to a story that poses some questions about just what The Doctor is allowed to do to change events that seem predestined. He was very clear to Rose in Father’s Day that she could NOT stop her father from dying.
But when presented with the death of one of his own great-grandchildren in the future he has to find a way to, in Wyn’s words, “Make this not have happened.” It is pushing the envelope slightly to say that he is allowed to change things that happen in the future but not the past. Or is it? In Back To The Future II, the sequel of the film quoted in this story presents an example of how future knowledge can make things go disastrously wrong. But on the other hand the same film trilogy shows how a little limited foreknowledge can be useful. And then consider something like A Christmas Carol. With knowledge of his future, Ebenezer Scrooge has the chance to change it. Fiction seems to be in two minds about whether the future is safe to be changed. I came down on the side of A Christmas Carol and let The Doctor alter what had not yet happened from his point of view. But he did it in a subtle way. He didn’t stop Davie from getting into the prototype time machine. He just urged him to give it a dry run first. Davie made the decision to do as he said.
The twins as young men in a future we hadn’t yet seen, was something I had been toying with for some time. I considered how their personalities might develop and Davie was clearly the mechanically minded of the two, the one who would want to build his own time machine. Their personalities are reflected in their now different hairstyles. Chris, the dreamer, has a pony tail. Davie the mechanic has short hair with blonde streaks.
The De Lorean. Yes, it’s a BIT corny. But after all, if you’re going to make a time machine out of a car what ELSE would you use? As it happens, Episode two of David Tennant’s second series saw a reference to the same film. So it’s a cultural reference not out of place in Doctor Who. And it DOES allow for one of the comedy moments before things became serious.
A faulty dimension chip in an actual TARDIS probably wouldn’t do what it did in the Prototype, of course. It would more likely reduce the TARDIS and its occupants to small size, as was seen in Logopolis for a different reason. Removing the chip was a plot device, of course in the William Hartnell story The Time Meddler. The Monk’s TARDIS interior was reduced to the size of a doll’s house by The Doctor’s clever ruse to outwit him.