Wonderful episode! And did you catch that very young Stuart Damon as the actor in Straker's office? This role couldn't have been very long after his Prince Charming role in Rodger's and Hammmerstein's Cinderella. Wild, isn't it?

This is the best ep ever, says I.

Damon would turn up again in an Anderson production, appearing twice on Space: 1999. He appeared briefly in the first season episode "Matter of Life and Death" as Eagle pilot Parks. He appeared in a much more substantial role in the second season two part "The Bringers of Wonder," playing an alien disguised as Guido Verdeschi, brother of Moonbase Alpha second in command Tony Verdeschi.

This is an episode only UFO could do in this manner. It provides more proof of what a great show it was. I like how Straker's hallucinations were tied into his recent frosty encounter with Mr. Burns...he assumed Burns identity!

This ep has a strange appeal because many of today's shows offer behind the scenes documentaries for their DVD releases. This show already provided its own behind the scenes footage. Needless to say, the "Sylvie" character was modeled after Sylvia Anderson who liked to be on set often!

It also has to be admitted that this ep requires too much of a suspension of disbelief. Seeing the sets as sets was fun, but it was just too much for me!

Treklon, the Sylvie character wasn't just modelled after Sylvia Anderson, but played by her!

Also, during Straker hallucination, Foster assumes the role of 'Mike', as in his real name 'Michael Billington', and General Henderson is referred to by his real name, 'Grant' (Grant Taylor).

As much as others like this episode, I find the backing up and revealing SHADO HQ and Moonbase as mere TV sets takes me out of the show.
There are also long stretches of the episode, during Straker's hallucination, where there's no background music.

Conroy is played by Al Mancini, who looks Latino, which explains why his hallucination involves Mexican banditos on Moonbase, and how he imagines himself as one, too. However, what's with the last name 'Conroy' if he looks Latino and has these delusions?

A confusing scene at SHADO; a female operative says that Sky 4 is changing course, and then the next line (I think from Foster) calls it Sky 1! Huh?
There's also an odd mistake that happens twice later on in the same scene-- the Moonhoppers are referred to as 'Mobiles', a completely different Earth-based vehicle that SHADO uses.

The death-count for this episode matches something like Star Trek's; 3 people killed on Moonbase, and 3 more at SHADO HQ.