Doctor Who Series 10: 14 Easter Eggs & References You Might've Missed In 'Smile'

5. Erehwon

The colonists' ship in this episode is called Erehwon 190484. Disregarding the numbers for a moment, you might notice that Erehwon is 'nowhere' spelled backward.

There may be more to it than that, though. Erewhon (with the w and h transposed) is a novel by Samuel Butler that was written in 1872. It is an early work of sci-fi dystopia. In the novel, Erewhon's inhabitants don't use machines as they fear that they will become sentient and rebel against their human masters. Sound familiar?

As for the numbers, they could also be a nod to another literary dystopia. In George Orwell's 1984, the opening line establishes that the story takes place in April. So the number could be the date 04/1984 jumbled up.