refurbished for the serial, adding new eyestalks, a dish receptor, improved bases for movement, and a new pedal mechanism. The serial's score was composed by Francis Chagrin. Around 18 minutes of incidental music for the first three episodes was recorded on 10 September 1964 at Maida Vale Studios, and 12 minutes for the final three episodes was recorded by five musicians on 8 October. Chagrin had conceived the music from the serial's final scene some time before production and was "dying to use it". Casting and characters On 12 March 1964, trade paper Television Today announced that Carole Ann Ford would depart from her role as Susan at the end of her contract, due to her dissatisfaction with the character's development. Whitaker wanted a strong reason for Susan's departure. To assist the story's development, Ford and Hartnell were invited to stay with Nation and his wife over a weekend in August. In June 1964, head of serials Donald Wilson considered continuing the show without the character of Barbara, and with a younger actress for Susan. Delays by Controller of Programmes Donald Baverstock to renew cast contracts meant that Susan's replacement, then intended to be Jenny (originally known as Saida), could not be introduced in the serial. Director Richard Martin asked Ann Davies, who was cast as Jenny, if she would be available as a regular cast member, but he could not offer the role. The Dalek Invasion of Earth was the first speaking role of Nicholas Smith, who portrayed Wells. When Smith discovered he was only starring in one episode, he approached Martin; Martin asked him to return in a later episode to lead the human rebellion. Jean Conroy, who played one of the women in the woods in the fifth episode, died in a street accident on 14 November; the episode was broadcast posthumously. Filming The Dalek Invasion of Earth was the first major location shoot for Doctor Who. Filming in 35mm began at Trafalgar Square at around 5:30 a.m. on 23 August 1964, consisting of shots of a deserted city. The design team added Dalek markings on landmarks such as Nelson's Column, which police requested they remove. On the same day, filming took place at the statue of the Duke of Cambridge in Whitehall, Westminster Bridge, and the Royal Albert Hall. Martin had an agreement with police to vacate parts of central London for filming. Production resumed two