Wed, 25 June 2008
While visiting a market on the planet of Shan Shen with the Doctor, Donna Noble is offered a free fortune reading. The fortune-teller presses Donna to reveal her past and focuses on a point in her past on modern-day Earth where she was driving to her temporary job at H. C. Clements, despite her mother's desire that she take a permanent job nearby. As a large beetle-like creature climbs onto Donna's back, the teller convinces Donna to change her mind in the past, taking a right at the road junction per her mother's wishes instead of a left.
The narrative turns to the alternate history created by Donna's choice, far bleaker than the course of events established in previous episodes. The Doctor dies permanently during the Racnoss' attack on London ("The Runaway Bride"), killed by the water pressure before he could regenerate, because Donna was not there to convince him to leave. Royal Hope Hospital is taken to the moon and returned ("Smith and Jones"), but only one person, Martha's fellow medical student Oliver Morgenstern, survives. Martha Jones and Sarah Jane Smith are among the dead (the latter apparently having foiled Florence Finnegan's plan). The Titanic crashes into the centre of London, wiping out the city and irradiating most of southern England ("Voyage of the Damned"). In the United States, 60 million people are turned into creatures made of fat ("Partners in Crime"). The Sontarans attempt to turn Earth into a breeding world ("The Poison Sky"), which is stopped by Jack Harkness and his remaining Torchwood team of Gwen Cooper and Ianto Jones. However, Gwen and Ianto are killed and Jack is transported to Sontar.
Throughout all these events, Rose Tyler keeps appearing before Donna. Aware of the events to come, she steers Donna away from mortal danger but refuses to give her name. After the latest tragedy, Rose urges Donna to come with her, even though she will die. Donna initially refuses, but three weeks later, as she and her grandfather talk about recent events, the stars begin disappearing throughout the sky. Donna tells Rose that she is ready.
Rose escorts Donna to a UNIT base where the dying TARDIS is being used to help power a makeshift time machine. Rose uses the system to show Donna the beetle that crawled onto her back during the fortune-telling. It is in temporal flux and cannot be removed, but Rose explains that Donna herself is also a point of flux. In order to set things right, they prepare to send her back in time to stop herself from going right. Donna agrees to go, but when she asks if she will get to live this time, Rose remains silent. Donna is sent back in time, but ends up half a mile away and with only four minutes to spare. Finding herself short of the mark on the road leading from the right of the critical intersection, Donna remembers what Rose said about her death and throws herself in front of a removal van. Traffic backs up to the intersection and the past Donna turns left, unwilling to wait for it to clear. As the future Donna lies on the ground, Rose leans over and whispers two words to pass on to the Doctor.
Back on Shan Shen, the beetle falls off of Donna's back and the fortune teller flees, frightened by this unexpected development. The Doctor finds Donna and the beetle. He explains that it normally affects only the person it attaches to (the universe merely "compensates"), but in Donna's case created a parallel world. The Doctor is curious about the other alternate realities that seem to form around Donna ("Forest of the Dead"). He ponders the coincidences surrounding Donna and himself, as if something is binding them together. When Donna insists that she is nothing special, the Doctor tells her that she is brilliant, which triggers her fading memories of Rose. She tells him about Rose's warning that "the darkness is coming" and that it is affecting all worlds. At his insistence, Donna tells him the words Rose said; "Bad Wolf". Horrified, the Doctor runs outside to find that the words "Bad Wolf" are everywhere, even on the TARDIS. Inside the Cloister Bell is ringing and the TARDIS interior is glowing red. When Donna asks about the meaning of "Bad Wolf", the Doctor replies, "It's the end of the universe."
This episode revisits the events of most of the present-day stories since Donna first met the Doctor, including "The Runaway Bride", "Smith and Jones", "Voyage of the Damned", "Partners in Crime", and "The Sontaran Stratagem" / "The Poison Sky". The Doctor's absence during these events leads to the deaths of Martha Jones, Sarah Jane Smith, Gwen Cooper and Ianto Jones. Jack Harkness, who cannot be killed, is transported to Sontar.
Torchwood characters Gwen Cooper and Ianto Jones are referred to by name for the first time in Doctor Who, while a short segment of music from the soundtrack of Torchwood plays in the background. Sarah Jane Smith is mentioned for the first time since "The Girl in the Fireplace", along with the first mentions of The Sarah Jane Adventures characters Luke Smith, Clyde Langer, and Maria Jackson.
The recurring "Bad Wolf" motif, primarily from series 1, returns at the conclusion of this episode to warn the Doctor of the events that are causing Rose to return. The TARDIS's Cloister Bell, last used in "Time Crash", can also be heard at the end of the episode. Sylvia Noble mentions that the bees are disappearing, which has been mentioned by Donna in "Partners in Crime", "Planet of the Ood", and "The Unicorn and the Wasp".
Donna's father Geoff, who appeared in "The Runaway Bride", is mentioned for the first time since "The Fires of Pompeii". It is implied that he was ill during the timescale of "Smith and Jones", and had died by the time of "Voyage of the Damned". His character was intended to be used during series 4, but was retired after actor Howard Attfield died before his scenes were finished. He was replaced by Bernard Cribbins, whose previous role as an anonymous newspaper seller was merged with that of Donna's grandfather.
The "Time Beetle" on Donna's back is described by the Doctor as part of "the Trickster's brigade". The Trickster was a time-altering villain in The Sarah Jane Adventures story Whatever Happened to Sarah Jane?. The beetle on her back was also referenced by Lucius Dextrus in "The Fires of Pompeii" with the line, "Daughter of London, there is something on your back!".
Sarah Jane Smith is said to write for the fictional Metropolitan magazine as previously mentioned in Planet of the Spiders.
Rose mentions the "causal nexus", which was discussed by the Doctor and the Master in "Logopolis."
The episode, filmed at the same time as "Midnight", saw the Doctor with very little screen-time, while "Midnight" saw Donna with little screen-time. Tennant shot all his scenes, at the episode's beginning and end, in one day, while a double stood in for the shot of the dead Doctor's arm.
The appearance of the Giant Spider of Metebelis 3 that clung to Sarah Jane Smith's back in Planet of the Spiders influenced the design and concept of the "Time Beetle" that clings to Donna's back in this episode.
 Cast notes
Billie Piper makes her first substantial appearance on the show since "Doomsday". Interviewed for Doctor Who Confidential, Piper said her return had been planned at the time of her original departure but that around three weeks before filming she decided to rewatch some of her old episodes to refamiliarise herself with the role and ease her doubts that she could play Rose again.
Clive Standen reprises the role of Private Harris (credited in this episode as "UNIT Soldier") from "The Sontaran Strategem" / "The Poison Sky". Here he is shown to have been in attendance during the Webstar crisis. Ben Righton reprises the role of Oliver Morgenstern from "Smith and Jones", in this episode the only survivor when the hospital is returned to Earth, Martha Jones having given him the last oxygen pack. Lachele Carl returns as American newsreader Trinity Wells, who previously appeared in the Doctor Who episodes "Aliens of London"/"World War Three", "The Christmas Invasion", "The Sound of Drums" and "The Poison Sky", in addition to The Sarah Jane Adventures story Revenge of the Slitheen. Chipo Chung, who plays the fortune-teller, previously appeared as Chantho in the episode "Utopia".
Based on BARB overnight returns, "Turn Left" was watched by 7 million viewers, giving it a 35% share of the total television audience. The episode received an Appreciation Index score of 88 (considered "Excellent").
Keith Watson for the Metro newspaper called it a "daring" episode and praised Catherine Tate's performance, which was "perfectly suited to a complex story... Doctor Who could get away with being a lot less clever. But they actually care about what they do." However, Sam Wollaston of The Guardian felt Tate was overshadowed by the return of Billie Piper. "Catherine Tate really puts everything into this episode (too much, maybe). But as soon as Rose shows, Donna's a goner."