Aliens of London
Aliens of London was the fourth story in the first series of Doctor Who. It was notable for featuring the first cliffhanger in the BBC Wales run, by virtue of starting the first two-part story. Keeping cliffhangers in the show allowed Davies to expand the plot and restore a well remembered part of the original series.
Narratively, the episode introduced the Slitheen, who would return to Doctor Who and The Sarah Jane Adventures. It marked the first appearances of Toshiko Sato, who would later feature as a regular character on Torchwood, and the recurring character of British politician Harriet Jones. It also introduced UNIT to the revived series.
One of its legacies — sometimes forgotten by writers — was offered in its pre-title sequence. As the Ninth Doctor mistakenly brought Rose Tyler one year into the viewer’s future, the “present day” of Doctor Who and its two BBC Wales spin-offs were generally considered to be one year later than the year of initial broadcast.
It was also the final episode of Doctor Who to have any portion recorded at BBC Television Center.
Rose and the Ninth Doctor have returned to the Powell Estate. Rose, thinking she has only been gone twelve hours, heads off to see her mum. Meanwhile, the Doctor notices a poster depicting a missing girl.
Jackie is shocked to see Rose. As she hugs Rose, the Doctor enters and informs Rose that she’s been gone twelve months, not hours. Jackie has been frantic with worry, but now she begins to scold Rose for not getting in touch with her. Interviewed by a policeman, the Doctor says that Rose is his companion. Jackie hits the Doctor.
Later, Rose and the Doctor chat outside. Rose can’t tell her mother about what she has done. Both are shocked to see an alien spaceship pass overhead and clip Big Ben before crashing into the river.
Rose and the Doctor try to visit the scene but are prevented by traffic. They head for home to watch the news on television. Several people are visiting, while the Doctor tries to watch the news. He sees General Asquith entering the hospital where the alien has been taken. The news also reports that the Prime Minister is still missing.
At the hospital mortuary, Dr Sato performs an autopsy on the alien. Meanwhile, several important figures gather at 10 Downing Street, including Joseph Green. He is informed by Indra Ganesh, the junior secretary, that he is acting Prime Minister for the crisis. As Ganesh attempts to lead Green away, he is accosted by Harriet Jones, MP for Flydale North, who wishes to meet with the Prime Minister but is brushed off. Green meets with Margaret Blaine and is given the emergency protocols.
The Doctor decides to leave the party, giving Rose a TARDIS key before he leaves. Mickey arrives, and Rose learns that several people, including Jackie, had suspected him of murdering Rose.
The Doctor uses the TARDIS to get to the hospital. He accidentally walks into a room of soldiers, but when they hear screaming, they all run out of the room and the soldiers listen to the Doctor’s orders. He finds Dr Sato, who says that the “dead” alien is alive and has run off. Despite the Doctor’s command, one of the soldiers shoots the alien dead.
Back in the Cabinet Room, General Asquith meets with Green and Blaine, who are acting strangely. He attempts to relieve Green of command, but Green, Blaine and another man, Oliver Charles, unzip their foreheads. Asquith screams. Unknown to them, Harriet Jones has sneaked inside the room and watches them from her hiding place.
The Doctor informs Dr Sato that the “alien” is fake. He then leaves. Outside, as Mickey is gloating that the Doctor has left Rose, the TARDIS materializes and the Doctor is back. After Jackie sees the TARDIS interior, she goes upstairs and calls a number to report the Doctor.
The Doctor deduces that the spaceship landing was faked as well. It originated from Earth, and whoever did it has been here for a while. He notes that UNIT has been called in to deal with the crisis.
The trio of Green, Blaine and Asquith complain about compression and gas exchange. They receive a code nine — the Doctor, an expert in extra-terrestrial affairs, has been located.
When they step out of the TARDIS, they are surrounded by police and helicopters. Mickey runs away, and the Doctor and Rose are arrested. They are taken to Downing Street, where the Doctor is brought in to meet with the other experts. Rose does not have proper clearance, so Harriet offers to stay with her. Meanwhile, a policeman visits Jackie for information.
The experts are gathered with Green and Asquith in a small room. Harriet takes Rose to the Cabinet Room and tells what she saw — Green and Blaine are aliens in skin suits who killed Asquith and the Prime Minister.
The Doctor figures out why the spaceship crash was faked — to get the Earth’s experts in one place. The policeman visiting Jackie begins to unzip his forehead. Ganesh, Rose and Harriet are caught by Margaret Blaine, who unzips her forehead. In the room below, Asquith unzips his forehead, and Green uses a remote control to electrocute the experts.