died before doing so. The serial used sound effects extensively. Casting and characters Camfield was impressed with Glover's performance in An Age of Kings in 1960, which led to his casting in the serial. Glover expressed excitement to work with Camfield, and to work with Russell again; he found Hill welcoming, but felt that Hartnell was not fond of him. When it appeared that Glover may not be available, Camfield interviewed Nicholas Courtney for the role, having known him at school in Egypt, but felt that he was not suitable. Marsh was cast as Joanna; she had previously worked with Hartnell in Will Any Gentleman...? (1953), during which she met her husband, Third Doctor actor Jon Pertwee. Adrienne Hill was also considered for the role, and read for Camfield and Lambert; they decided that she was not tall enough. Marsh recalled that she and Glover decided to act "slightly too loving for a brother and sister", which Lambert noticed and noted. The European actors in foreign roles were "blacked up" for the serial by the make-up department. Walter Randall was cast as El Akir, having been good friends with Camfield since working together on Gerry Halliday in 1951; Randall previously appeared in the series as Tonila in The Aztecs (1964). Several other actors had also appeared in previous serials, namely Marco Polo. Filming Early 35mm stock filming took place from 16–18 February 1965 on the sound stages at BBC Television Film Studios. Russell was released from rehearsals for "Invasion" (the fifth episode of the preceding serial, The Web Planet) to perform action sequences on 16 February to accommodate for his holiday during the filming of the third episode; the first action sequence, a fight with a Saracen warrior, was choreographed by fight arranger Derek Ware. For a shot in which ants advance upon Ian in the fourth episode, assistant floor manager Michael E. Briant arranged for the supply of 75 black ants from London Zoo. Russell refused to perform a shot in which the ants move up Ian's arm to his hand; Camfield's production assistant Viktors Ritelis doubled for Russell instead. Hill was released from rehearsals for "Invasion" on 18 February to film for the serial. Rehearsals for the first episode began on 1 March 1965. Weekly filming began in Studio 1 at Riverside Studios on 5 March 1965. For the first episode, a trained hawk was supplied by John