A troubled production
I agree with all the comments about this being a memorable movie and if things had worked out better it could have been a masterpiece. Unfortunately from what I have read about the production dear old Hammer somewhat lost their nerve about what Joseph Losey had served up to them. Rather like the distributers of The Wicker Man lost their nerve later.
The question that caused Hammer problems is the same question that plagued the Wicker Man - namely "what was it?!" Its not quite a scifi but its not quite a horror - is it a "message" movie about nuclear disarmament - is it a tale of disaffected youth?
Hammer apparently cut the film about something terrible before releasing it as the support half of a double bill in 1963 - the big film was Maniac. And if you watch the film carefully you can see some awkward chop and changes - the film story "lurches" about quite a bit which presumably where the cuts occurred.
One final point the statues created by Vivica Lindfors were specially sculpted by one of Britains leading sculpters of the time - Elizabeth Frink.
Somebody should go back and research the making of this neglected fim in depth - such has been done with movies like Wicker Man and Django. It deserves it.