10 Best Doctor Who Time Travel Stories
5. The Ark
Having unwittingly exposed a future human civilisation to the common cold, the Doctor and his companions race against time to find a cure and save the day. Leaving in the TARDIS, they are surprised to materialise in the exact same spot, seven centuries later.
The Doctor and his companions' previous visit eventually led to a bloody uprising by the enslaved Monoids who now oppress their former captors. Would any of this have happened if the TARDIS hadn't arrived? Well, possibly, yes but it's the virus that has exposed the inequality on board the ark ship.
This 1965 story is a real underrated classic, and has increases in relevance as we continue to deal with the pandemic. Steven's concern over what else the travellers have exposed other civilisations to is one of the most chilling moments in all of Doctor Who.
The very fact that the Doctor has a time machine allows us, as an audience, to experience the world that the Doctor leaves behind once he's "saved the day". It's a shame the series doesn't do it more often.