"This episode was originally planned for transmission on Saturday 28 November 1964, but was then pulled forward a week and shown on 21 November." "11.4 million people were watching, attracted by extensive publicity during the previous week." "This is Peter Diamond, and he's a stuntman." "This location sequence was filmed on 27 August 1964, under the railway bridge at Kew." "It was originally planned to film under the south end of Hammersmith Bridge." "The change to Kew was made for reasons of design logistics." "Set designer Spencer Chapman suggested it when he realised that a studio set would need not only to reproduce a major London bridge but also simulate its collapse later in the episode." "The heat of the studio lights regularly caused malfunctions in the ship's console prop." "This serial was first conceived shortly after the Daleks finished their first run in Doctor Who in February 1964." "Terry Nation was formally commissioned to write it on 17 March." "At that stage, the working title was 'The Daleks', but it had become 'The Return of the Daleks' when Nation delivered the storyline in mid-April, and then 'The Invaders' in the first draft scripts." "One production aim was to make the new serial more spectacular than the Daleks' first appearance, which is why Nation decided to bring them to Earth this time." "The draft script laid down the basic story structure, and parts of the dialogue were the same as in the transmitted version, but there were also some differences of incident, mood and emphasis." "For example, in the first draft, it's too misty to see very far, and Ian trips over a dead human body lying face-down in the mud." "Note the open windows of the police box prop." "According to the script, "Ian and Barbara are really too excited and pleased to look for flaws."" "They have, after all, been trying to get back to the 1960s for the entire first year's run of Doctor Who!" "Despite Barbara's evident happiness, though, Jacqueline Hill's performance subtly pulls focus onto something wrong - the small tree she's fiddling with." "The set design suggests urban decay by showing foliage starting to take over the neglected city." "To dress this set alone, the production team ordered:" "nine large bushes, five trees, large quantities of weeds and creeper and an unfeasible amount of marsh grass, not to mention four bags of peat and four packets of fuller's earth." "In the first draft, Susan is startled by an owl flying out unexpectedly." "Carole Ann Ford did the fall herself." "The shots were intercut to suggest that she had fallen further than she did." "Watch carefully here, and you'll see that the police box prop is backless." "In the early episodes of Doctor Who, the scriptwriters always had somehow to separate the travellers from the Doctor's ship." "Otherwise, they could just hop in and go somewhere safer!" "Watch the background as Ian pushes at the girder." "His efforts dislodge one of the plants further up, as if the entire structure is still precariously balanced." "The whole design here shows meticulous attention to detail." "Almost everything in the under-bridge set is carefully copied from the real location, and, in particular, Kew Rail Bridge really is made of latticed girders like this." "The studio recording for this episode, on 18 September 1964, was very fraught, and a number of scenes had to be re-shot." "This is the second take of this sequence." "The first was abandoned because one of the actors was out of position here." "Part of the problem was the complexity of some of the sets, including the collapsing bridge." "The scene crew struggled heroically, shifting what the floor manager later described as "exceptionally filthy sets", but resetting the "trick pieces" used up so much time in camera rehearsals that only one full run-through was possible before recording began at 8pm." "Even so, the cast and crew managed to get the episode in the can in the allotted hour-and-a-quarter's recording time." "In the script, the Doctor also says that they have heard "no plop of malin on the water"." "In the first draft, Susan is knocked unconscious by the fall, and there is a momentary suggestion that she might have been killed." "After the draft was completed, around June 1964, there were two more stages of script development." "Terry Nation reworked the serial extensively, producing a rehearsal script in time for location filming in late August, and this was further refined to produce the camera script for the studio recording in September and October." "Even then, there were a few dialogue changes made by the actors in the studio." "For example..." "The bottom-smacking threat was William Hartnell's unscripted contribution." "In the rehearsal script, Barbara doesn't leave Susan on her own." "She helps Susan to her feet, and they go down to the river together." "Terry Nation (1930-97) was mainly known as a comedy writer before he created the Daleks in 1963." "He began his career in 1955 writing for Spike Milligan, and later became Tony Hancock's chief scriptwriter." "But the Daleks propelled him into a new genre." "In 1964, he became heavily committed to television thriller series." "When he was writing 'The Dalek Invasion of Earth', his weekday job was scripting the Roger Moore series The Saint." "Doctor Who was weekend work." "Nation estimated that it took him eight hours to write each of the six scripts." "He also had time for a house party on Saturday 8 August, when he was finishing off the rehearsal scripts." "Two of his guests on that occasion were William Hartnell and Carole Ann Ford, who had been in revolutionary France the day before, recording the Doctor Who episode 'A Bargain of Necessity'." "This set was designed to make the best use of the limited space available in the studio." "Watch how Barbara is positioned relative to the poster in this shot and the next." "She enters this shot from a completely different direction!" "That's because the set represents more than one location when seen from different camera positions, so here, the poster is actually visible behind them, not where Barbara points." "The small dimensions of the allocated studios were a perennial problem for early Doctor Who." "For this demanding serial, producer Verity Lambert had the production moved to a larger-than-usual studio." "This was at Riverside Studios, now an arts centre, but then a dingy industrial complex not far from where the riverbank location scenes were shot." "Studio One, where all six episodes were recorded, measured just 68 feet by 64, so with ten sets required for this episode, space was still at a premium!" "In the first draft, the warehouse is a chemical store, and Doctor Who (as he is called) deduces from some spilt acid that someone has been there recently." "From the window, Ian sees Nelson's Column in the distance and realises for the first time that they're in London." "The nuclear reactor and the second missing chimney were unscripted embellishments by the department that supplied the caption slide." "In the rehearsal script, Ian seems to think the old power station has been superseded by nuclear power and left derelict, whereas in the transmitted version, it has obviously been converted into an atomic facility." "It's 2041 in the first draft." "This riverside sequence was especially controversial when the episode was first shown." "The corpse in the river was considered excessively gruesome." "The television critic of "The Listener" even banned Doctor Who from his household!" "This sequence was a very late addition." "Even in the camera script, Barbara is simply gripped on the shoulder by a hand." "By the time Robert Aldous was cast to play the insurgent, it was too late to put him in the episode's closing credits reel." "The omission was rectified when the episode was billed in the "Radio Times"." "This sequence had to be re-shot, partly because an actor dried, and partly because the box failed to fall on cue." "Terry Nation originally envisaged less cumbersome and less conspicuous headgear for the Robomen." "The draft script specifies, "On the left temple is a disc as big as a half-crown"" "(that's about three centimetres across)." ""Two thin wires emerge from it and vanish into the hair."" "What's most obviously out of the ordinary about them is the "large, badly stitched scars" on the temple and forehead." "In the rehearsal script, the whip's thongs have vicious lead tips." "In the first draft, Doctor Who reasons that the catastrophe overcame London in the 1970s." "That's why the city still looks so much like it did in the 1960s." "His first thought is that humanity has been decimated by plague, as it was by the Black Death of 1351 and the influenza pandemic of 1918." "Ian assumes it was germ warfare between America and Russia, but Doctor Who points out that this would be suicide." "It's more likely that the aggressor was an alien power using bacteria to wipe out most of Earth's population before moving in." "Ian is doubled by Peter Diamond, whom you saw as the suicidal Roboman at the start of the episode." "Diamond did intermittent stunt work for Doctor Who between 1963 and 1971." "Among his film credits are From Russia with Love (1963), Star Wars (1977) and Raiders of the Lost Ark (1981), and his recent television work includes Heartbeat (1992-8), The Vice (1999) and Nice Guy Eddie (2002)." "The Shell petrol can seen here is a rarity in a 1960s BBC production." "Normally, all proprietary names would be carefully covered, to avoid any hint of advertising." "Susan yells for Barbara in the script." "Terry Nation suggested using a bomb-site at Ludgate Hill as the location for this sequence." "Mid-1960s London still had some unreclaimed areas that had been destroyed by World War Two bombing." "In the event, though, the sequence was filmed in a disused tube station at Wood Lane." "This building had been the boiler house until the station closed in 1947." "For the subway entrance, Nation suggested a flight of steps near Piccadilly Circus." "The Wood Lane scenes were all filmed on Tuesday 25 August 1964, and, as you can see, that year's hot summer provided perfect conditions for filming - a lovely sunny day!" "The background in this shot is a large photographic flat." "See if you can spot the strings." "They hold up the saucer laterally rather than vertically, because the eye naturally looks for wires directly above a flying model." "But lateral strings are less controllable." "That's why the saucer wobbles." "Things are more sinister in the first draft - we learn nothing about the unconscious Susan's abductor until the second episode." ""There were rumours of flying saucers in my time," says Ian in cut dialogue." ""I never really thought I'd see one."" "The Doctor reasons that "whatever has happened to London hasn't been caused by the people of Earth"." "The saucer is "an interplanetary machine", so "Earth has been invaded from another planet"." "The dialogue was cut after one of the actors asked for the shot to be recorded out of sequence, then dried on the take." "William Hartnell's not altogether comfortable with his lines because this passage of dialogue was a late addition." "In the scripts, this scene is set on the platform of a London Underground station." "The elephant poster was originally something more alarming:" ""PUBLIC WARNING!" ""Do not drink rainwater." "All water must be boiled before consumption." ""Issued by the European Emergency Health Committee."" "The rebels' "doorbell" was the letter "O" in "not"." "The designer changed this to the sliding vent opened by pressing the elephant's tusk." "In the first draft, David's surname was Sonheim." "He became David Archer in the rehearsal scripts, and was Scottified as David Campbell after Peter Fraser was cast in the role." ""Well, save some for me," replies David in the rehearsal script." "The end of the scene was a late addition." "In the camera script, Dortmun goes below with the others." "In the camera script, Ian is making a futile attempt to shift the girder with a crowbar." ""It would take a crane to lift this lot," he says." "This stretch of the Thames was already heavily polluted in the mid-1960s, so one of the less pleasant aspects of the location filming at Kew was the smell of the river." "This whole sequence was a very late addition." "In the camera script, Ian finds a grubby handkerchief, which the Doctor identifies as Barbara's." "They decide that the girls were frightened by the gunfire and hid from the flying saucer." "And in the background, the Robomen close in." "The music for this serial was written by the Bucharest-born composer Francis Chagrin (1905-72)." "It was played by five musicians and conducted by Chagrin himself." "An active supporter of new music, Chagrin originally trained as an engineer in the 1920s." "He studied music in Paris, then came to Britain in 1936." "His classical compositions included two complete symphonies (1959 and 1970), and his many film scores included An Inspector Calls (1954) and The Colditz Story (1955)." "In the first draft and rehearsal scripts, the saucer lands in Trafalgar Square." "This is the second take of this sequence." "The first was abandoned because the camera was off position." "At this point in the draft script, Barbara is still wandering around looking for Susan." "She is trapped by three Robomen outside the Underground entrance, and flees into the tunnel, where she is seized and taken away by an unknown assailant." "Meanwhile, Doctor Who and Ian are also caught by the Robos and taken to the saucer in Trafalgar Square." "A section of the spaceship's underside lowers itself to form a ramp, and, with a "rumbling sound of wheels rolling over metal", something comes out." "Ian and Doctor Who register astonishment, and the shot cuts to show four Daleks on the ramp!" "In the rehearsal script, this was changed to a more surprising cliff-hanger..." "This is a model shot..." "..but the other shots of the Dalek in the river were filmed on location at Hammersmith Bridge." "Uncredited production contributors to this serial included:" "Christina Lawton (Assistant Floor Manager)" "Ray Day, Mike Catherwood (Floor Assistants)" "Cyril Julius, Mark Lewis (Technical Managers)" "Carolyn Bill (Director's Secretary)" "Jane Shirley, Tristan de Vere Cole (Production Assistants)"