This episode was filmed at Radlett Preparatory School in Hertfordshire.
Another similarity to Captain Scarlet happens when one of the astronomers is killed while looking through his telescope at Venus. In the Captain Scarlet episode "Shadow of Fear" an astronomer is killed in a similar manner at his telescope while watching the planet Mars.
The eerie sound effect used in this episode when the astronomers are killed is the same effect used in the Captain Scarlet episode "Attack on Cloudbase" (which aired just over a year after this episode) as the noise the Mysteron flying saucers make when they fire their weapons.
The closing sequence of the Steed/Peel black and white series involving their departure on various forms of transport was dropped for the colour series. Instead they used a teaser at the start of each episode. In each teaser, Steed informed Mrs. Peel that they were required for official business. A different method was used each time. In this episode, Emma is practising her fencing technique in her flat. As she lunges at a sack figure on the back of her front door, Steed enters and pierces a card on the end of her sword that reads, 'Mrs. Peel - we're needed.'
The tag line used at the end of opening credits: ' Steed is shot full of holes and Emma sees stars!'
Steed is determined to join the British Venusian Society.
Venus: We are a very select group.
Steed: Good. I abhor overcrowding.
Venus: With stringent rules.
Steed: I shall obey them stringently.
Venus: And a very high subscription.
Steed: The sky's the limit, to coin a phrase.
This episode was filmed at Radlett
Preparatory School in Hertfordshire.
Tag Scene: Steed hurries Mrs. Peel along by suggesting that they are 'invited to have dinner on 'Venus' - the Venus Browne society, that is.
The incidental music that plays during the teaser is highly reminiscent of "Venus, the Bringer of Peace" from Gustav Holst's "The Planets".
This is the first 'The Avengers' episode in colour.