Gridlock (Doctor Who)

"Gridlock" is the third episode of the third series of the British science fiction television series Doctor Who, which was first broadcast on BBC One on 14 April 2007. It was written by Russell T Davies and directed by Richard Clark.

The episode is set five billion years in the future on the planet New Earth, one of the many planets humanity had settled on. In the episode, alien time traveller The Doctor (David Tennant) and his new travelling companion Martha Jones (Freema Agyeman) discover the remainder of humanity on the planet live in perpetual gridlock within the Motorway, a highway system beneath the city state of New New York. When Martha is kidnapped, the Doctor races to find her before she enters the dangerous "fast lane".

"Gridlock" completes a loose trilogy that began with "The End of the World" and "New Earth" (2006), and contains hints at the series' story arc. The story is designed to show how the Doctor can bring hope into a world. Production of "Gridlock" took place in September and October 2006. Much of the episode was filmed in-studio and used a large amount of computer-generated imagery, so it appeared to be set in a "CGI world". Some location filming was done in Cardiff, most notably at the Temple of Peace. "Gridlock" was viewed by 8.41 million viewers in the UK and received generally positive reviews from critics.

The Tenth Doctor takes Martha to an alleyway in the city-state of New New York on New Earth where street vendors are selling addictive mood drugs in the form of sticky patches to help people deal with their emotions. A young couple named Milo and Cheen kidnap Martha. Once in their vehicle, they explain that Cheen is pregnant and that they needed three adult passengers with them to use the fast lane. They promise they will drop Martha off when they reach their destination ten miles away, estimated to take six years. The Doctor chases after Martha's kidnappers and arrives at the Motorway, a completely enclosed highway filled with thousands of hover vans stuck in gridlock. One of the motorists, Brannigan, helps the Doctor locate the vehicle containing Martha, which is heading towards the fast lane. The Doctor tries to call the police but gets put on hold, so the Doctor decides to try to reach Martha himself by breaking into and out of vans on the way to the fast lane.

Martha, Milo, and Cheen drive into the fast lane and see crab-like Macra, who attempt to capture and eat those that fly in the fast lane. The Doctor watches as Milo's van is nearly caught by a Macra claw, but Martha realises that the beings are attracted by the light and motion generated by the van and has Milo cut the power to hide in the fog. Novice Hame finds the Doctor and teleports him against his will to the Senate of New New York. Hame explains that a virus mutated in the drug "Bliss" and wiped out the entire surface population. Eventually the virus also perished. Those in the Motorway were spared by being sealed in and the planet was quarantined. The Face of Boe wired himself to the system to keep the Motorway operational but could not unseal it himself. The Doctor works with Hame to unseal the Motorway. The Face of Boe gives the last of his energy to the system, allowing the ceiling of the Motorway to open and freeing the motorists. When Martha arrives at the Senate, the Face of Boe, close to death, imparts his final message to the Doctor: "You are not alone." The Doctor tells Martha that the Face of Boe is wrong; he is the last Time Lord and his planet was destroyed in the Time War.

"Gridlock" is the third in a trilogy which began with series one's "The End of the World" and series two's "New Earth". Novice Hame and the green crescent seen on the mood patches previously appeared in "New Earth". Head writer and executive producer Russell T Davies wanted to visit the same world each year to maintain a sense of continuity, something that could be hard to do with Doctor Who's formula. Producer Phil Collinson remarked that "Gridlock" displayed Davies' tendency to write about "topical" issues; it is set in a dark dystopian future, but is also a satire on the common traffic jam. While the story is bleak, Davies showed how the Doctor transforms the place by literally opening up the sky and bringing in light. Davies also used hymns to signify hope and a togetherness of the members of the Motorway. Those on the Motorway sing "The Old Rugged Cross", and the hymn heard at the end of the episode is "Abide with Me". The episode also displays the Doctor's growing attachment to Martha; he feels guilty for lying to her and bringing her to New New York just to show off and realises that he misses her when she is taken.

Davies stated that he based many aspects of New New York on Mega-City One from the anthology comic 2000 AD, including the businessman's appearance on Max Normal from the Judge Dredd comic books. The numbered mood patches parallel the number coded mood controllers in the Ninth Doctor novel Only Human by Gareth Roberts; Davies confirms that this was his inspiration. The character of Sally Calypso was an homage to Halo Jones, which featured a similar character named Swifty Frisko. Also in the online commentary, Davies noted that Brannigan's appearance was based on "Ratz", the CGI disembodied cat's head that was a "virtual presenter" of CBBC's Live & Kicking in the early 1990s. Ma and Pa at the start of the episode are based on the farming couple in the painting American Gothic, both having identical hairstyles, glasses and fashions. Alice and May Cassini are the first homosexual married couple featured in Doctor Who.

The episode marks the second appearance of the large crustacean Macra race, who previously appeared in the Second Doctor serial The Macra Terror (1967). In "Gridlock", they have "devolved" from their previous, more intelligent, state. Davies thought it was "cute" to bring back a forty-year-old monster whose story is now missing. "Gridlock" also contains important hints about the story arc of the series as it reveals the "great secret" promised to the Doctor by the Face of Boe in "New Earth" – "You are not alone". The Face of Boe was originally intended to die in "New Earth", but as that episode featured another death, it was put off. The meaning of Boe's final words are revealed in "Utopia", while "Last of the Time Lords" suggest – but is purposely never confirmed in-universe – that the Face of Boe's true identity is Captain Jack Harkness (John Barrowman).