• When Eddie Kerr's helijet is landing, you can clearly see the roof has been removed for overhead camera shots, and to let the puppet's strings through.
  • As Eddie is standing in front of the helijet he arrived in, you can see it is of a different design and colour to the one seen landing.
  • When the unnamed photographer raises his camera at Jenkins, a human hand can be seen assisting with the puppet's movement from below.
  • When the picture of the impostor is seen in the newspaper, humorously, the strings are visible.
TI 18
  • When Elliot picks up the radio microphone to call Search Control, between shots, his radio head-set (which is on his shoulders), has suddenly turned round. Similarly, when Hale says, "Three to four hours at least,", Elliot has his head-set on his head, but back to front.
  • During the search operation press conference, when the Air Force Officer is speaking, the puppet behind him (which previously played the Allington Suspension Bridge Controller) can be seen moving its mouth in sync with the dialogue as well.
  • As in The Uninvited, Alan does another quick change of clothes aboard Thunderbird 3 before climbing into the lift. Scott also does a quick change; when he arrives aboard Thunderbird 3, he is wearing a yellow suit and orange shirt, but just before blast off, we see him in his usual blue roll-neck sweater, brown trousers and grey checked jacket.
  • At the end of the episode, Scott says "You can say that again." without moving his lips.