The Trap (Captain Scarlet) - Production

Production

Script editor for Captain Scarlet and the Mysterons, Tony Barwick, was determined for Alan Pattillo to produce material for the series due to his experience as a script editor and writer for Thunderbirds. However, commitments to other projects meant that Pattillo was able to submit only one script. For "The Trap", the castle setting was prescribed by Gerry Anderson whom, Pattillo states, "always liked to have a Scottish subject in his series." Previous Supermarionation adventures set partly in Scottish castles include Stingray episode "The Loch Ness Monster" and Thunderbirds episode "30 Minutes after Noon", which both feature a miniature model that would make a reappearance in "The Trap" as Glen Garry Castle.

In the opening sequence depicting the XQR's destruction, the visual effect of the lightning bolt striking the aircraft would have been too much of a challenge to create live, and was therefore superimposed over the recorded film in post-production. Flames and smoke issuing from the crippled XQR were produced by Jetex fuel pellets attached to the side of the model turned away from the camera. Making its only appearance in "The Trap" is the Spectrum Magnacopter, the model of which was designed by Mike Trim. The scale interior sets, however, were the responsibility of the art department, which made use of mainly "flat sheet" rather than malleable materials in their designs: as a result, there are discrepancies between Trim's streamlined model and the art department's more angular puppet sets.

Alan Pattillo's script included challenging camera sequences which called for all ten "revamp puppets" that would portray the World Air Force leaders to appear in one shot. The character of Morton is portrayed by a puppet which had previously appeared in the episode "Point 783" as Colonel Storm, and which was modelled on American actor Robert Mitchum. Captain Scarlet and the Mysterons writers Chris Drake and Graeme Bassett also note the mixture of live action with Supermarionation puppetry in the dungeon scenes with the restrained Scarlet and Symphony, and their rescue by Morton.

The gun battle between Captain Scarlet and Goddard which forms the climax to "The Trap" posed a number of special effects challenges. In one shot, Goddard fires a line of bullets at the wall behind which Scarlet is concealed: to realise this effect, a strip of Cordtex explosive was lit at one end, resulting in a succession of miniature blasts as the flame travelled to the far end. The Glen Garry model was filled with petrol gel which, ignited, created an explosion to portray the destruction of the castle. Making only its second appearance in all of Captain Scarlet and the Mysterons in the climax to "The Trap" is the Captain Scarlet "grimacing head", which first features in the pilot episode when the character is similarly shot down by Captain Blue.

Incidental music for "The Trap", which includes tracks such as "The Fate of the XQR" and "Castle Glen Garry", was recorded by Barry Gray on August 27, 1967 (1967-08-27). The four-hour session also included recording for the 18th episode in the production schedule, "Model Spy", and used a 16-member orchestra. This is the first episode in the ITC recommended broadcast order to feature the lyrical version of the end titles song, "Captain Scarlet". However, the first produced episode with this revised version is "Lunarville 7".