Inspirations - New Earth

 

Russell T Davies was pleased with the positive response from fans and critics alike towards The End of the World in the 2005 series. He decided that another visit to the year 5 Billion was called for for the next series, and actually considered making this an annual event. (It would be back for the third series, but not for the fourth).

One of the highlights of the 2005 story had been Cassandra, as created by VFX house The Mill, and voiced by Zoe Wanamaker. Despite the character being killed off, he was determined to find a way to bring her back. A twin sister was briefly considered, before they settled on it being the same character. Whilst the skin had been destroyed, the brain had remained intact.

With a new Doctor starting out, it was important to have a bridge between the 2005 series and this one, so that younger viewers in particular would know that this was still the Doctor.

An issue in 2005, however, had been the expense involved in bringing Cassandra to life - both time and money. This is why RTD decided to have her mind leave her body fairly early on, and to inhabit those of Rose and the Doctor.

Another character whom RTD wanted to see used again was the Face of Boe. The prop had been very expensive to build, and yet had hardly featured. It had survived the events of Platform One, so was available for a return. The effects team made improvements to the animatronics, to make the face more animated. RTD intended that the Face would die in this episode, giving the Doctor the final cryptic message "You are not alone...". On learning that a third series had been guaranteed by the BBC, RTD decided to defer this.

The dying Face had helped to prompt the hospital setting.

RTD had always found hospitals to be slightly creepy locations. He had previously noticed this when writing for the CITV series Children's Ward. 

Michael Crichton had written a book called Coma, filmed in 1978. This saw people with minor ailments in a hospital being used for illegal organ transplants for rich people. Stories such as this had also featured in TV series like The X-Files, so there was a history of hospitals being settings for scary happenings.

Originally it was going to be a hospital on a totally alien planet, but he was still reluctant to have the series lose its connections with Earth and with human beings. A TV audience would connect with human characters, but not so much with totally alien characters. The 2005 series had been set entirely on or above Earth.

Making the setting New New York simply allowed the dialogue to play around with the word 'New' - New Earth, New New York, New x15 York etc.

The notion of the nursing staff being cats derived from RTD's opinion that cats were somewhat sinister, in that you could never work out what they were thinking. Making them nuns allowed for savings on masks, as their faces would be covered apart from three speaking characters. 

The look of the secret "Intensive Care Unit" was inspired by the interior of a Borg Cube from Star Trek: The Next Generation.

It was originally planned that all of the patients would be killed by the Doctor at the conclusion, put out of their misery as they were so infected he could do nothing to save them. It was felt that this was too depressing, and so the cure-all was devised. This was inspired by the conclusion to The Doctor Dances, where the Doctor could claim that everybody lives. RTD had read comments by Steven Moffat that he (Davies) would create likeable characters only to kill them off, and so he determined to disprove this here.

Chip was originally going to be a dwarf character.

Once in Rose's body, Cassandra considers herself a Chav. This was a British, especially English, word for a young loutish individual, working class, who liked to dress in designer clothing (real or imitation) and ostentatious jewellery (flashy gold). Cassandra-Rose attempts to speak Cockney rhyming slang. Whilst many Cockneys are Chavs, not all Chavs are Cockneys.

One of the illnesses which the Sisters claim to be able to cure is Hawtrey's Syndrome, at least in the short "Tardisode" prequel to this episode. Writer Gareth Roberts took this from the Carry On... actor's biography which was sitting on the shelf above where he was working.