10 Doctor Who Episodes That Accidentally Changed The Show Forever

With the show's original sci-fi/historical episode rotation out the window, it wasn't long before another, even bigger change to the format snuck its way in: visits to the present.

Nowadays, the Doctor defending contemporary Earth from alien invasions is so fundamentally woven into the fabric of the show that it’s taken for granted that it will happen at least once a year. So it may come as a surprise that it wasn’t until the finale of the show’s third season, The War Machines, that the TARDIS found its way back to 20th century London.

The story takes full advantage of its modern setting, featuring a swinging '60s nightclub, the newly-built landmark of Post Office Tower, and evil robots on the streets of London.

Though the titular War Machines never caught on as the potential Dalek replacements they were hoped to be, the story’s setting certainly did. It started something that would soon come to define the show, with the Doctor developing a firm fondness for our small blue planet – and even being trapped there for a few seasons in the early '70s.