What we have here is a vigorous John Barry espionage-a-go-go theme...given weird rhythmic feints and dodges and sour dissonances, foreshadowing Captain Scarlet's violent and darkly paranoiac atmosphere; it strikes me as somehow akin to the Doctor Who theme--a product of the same period--and the title track from Bowie's Station to Station.
So. I put it out to the more musically educated folks out in LJ-land: what's going on in this song, structurally, that would plunge it into the Uncanny Valley to a listener accustomed to Anglo-American rock and pop conventions?
"Captain Scarlet" + "theme song"+ "time signature."
"Captain Scarlet" + "theme song" + "review" (which yielded this: http://www.bbc.co.uk/music/reviews/v5zf/)
"Captain Scarlet + "theme song" + "tritones".
"Captain Scarlet + "theme song" + "locrian mode".