Inspirations: Face The Raven

Sarah Dollard was a Melbourne-based fan of Doctor Who who had written for Neighbours and other Australian series, before contributing to the BBC fantasy dramas Merlin and Being Human.

Her inspiration for this story began when a friend explained to her about Trap Streets. These were small non-existent thoroughfares added to maps by their makers to catch out cartographical copyists - as the only way the street could appear on any other map was if it had been plagiarised.

Dollard envisioned these streets as being real, but unknown to the general public. As such they could offer sanctuary to a group of people. It was Steven Moffat who suggested that these may be alien refugees. The idea that the Doctor and Clara might investigate a murder in one of these zones also came from the showrunner.

In order to get the Doctor and Clara into the mystery quickly, the script editor suggested reusing an established character, and graffiti artist Rigsy from Flatline was hit upon. In that story he had mentioned a mother living in London so it was decided that he had located there from Bristol, and he would be accused of a crime he did not commit - providing the motive for the TARDIS pair to get involved. The episode would therefore become a whodunnit.

Dollard then developed the idea that the isolating community had their own unique mode of dispensing justice - a creature which would be released from a cage to kill an individual who had been marked for execution.

This provided a countdown and a fixed timescale in which the Doctor had to come up with the real killer, so a race against time.

The entrance to the Trap Street was originally going to be through the door of a mural Rigsy had painted of the TARDIS. The Mayor was going to be a beetle-like alien, whose deputy was a Sontaran.

Once the episode was moved to tenth position in the series, leading into the finale, it was later decided to introduce the new character Ashildr / Me into Dollard's story as she played a role in the final episode. She then took on the role of Mayor.

Having already stayed on much longer than anticipated, this would be Jenna Coleman's last series. Moffat debated with himself having her leave in the finale or - for shock value - having her killed off earlier. (In the end, he would manage both).

It would be made clear that her death wasn't some form of self-sacrifice. Rather, she died due to her over-confidence and increasing lust for danger and excitement - a belief that she could match the Doctor's abilities. Me would not be held responsible and the Doctor would not be vengeful.

The raven features in many mythologies. 

Odin is also known as the Raven God. He had two pet birds which gathered intelligence for him and acted as spies.

In the indigenous cultures of the Pacific Northwest the bird is both a trickster and a bringer of light to the world.

Celtic mythology has them birds of ill omen, especially when it comes to battle.

The ancient Greeks held that they were servants of Apollo, and were originally white. Apollo singed them in a rage after they brought him bad news.

The design of the Trap Street was based on narrow lanes off Oxford Street in London, and The Shambles in York. Many have noted a similarity to Diagon Alley in the Harry Potter films though Dollard has said that this wasn't intentional.

Among the aliens we see in the street are a Cyberman, Ood and Sontaran.

Among returning guest artists are Robin Soans as "Chronolock Guy". He had played Consul Luvic in The Keeper of Traken. Me's deputy, Rump, is Simon Paisley Day who, as Simon Day, played the Steward on Platform One in The End of the World.

Next time: the Doctor gets caught up in the works and takes a very long time to extricate himself, in what many regard as one of the greatest Doctor Who episodes of all time...