(Spoilers ahead, but who cares?)
I think the operative word here is “mess.”
I mean, I assume that someone making this thing had some idea of what it was all supposed to be about, but unfortunately, he didn’t chose to share with us.
A grave breaks open, and a giant bird-man thing bursts out. The locals think that it has something to do with one of the local legends, but Robert Hutton’s scientist character knows that there is real science behind all this, with a lot of talk about needing lots of power, and how the old Easter Island legend of some sort of man-bird proves his scientific theory!
Well, obviously, Robert’s theory has to be correct, because we get to see a hidden mad scientist lab full of electrical equipment.
Not that that explains the skeleton he finds sitting at the control panel.
However, we’re not given long to think about that before we get the final reveal of the creature, as a big bird, with local mad scientist Akim Tamiroff’s face…
We are then left to make what we can of it all, with some odd little comment about “transference” thrown in as an explanation.
As Hammer and others did at the time, we have the usual American actors to make it easier to market this one in the US. However, they must have had some idea how this was going to turn out as we get no fewer than three American actors: Hutton, Tamiroff, and Broderick Crawford.
I do not know whether this was supposed to be a supernatural film which someone tried to slap a scientific-ish explanation onto, or whether the script fails to make their explanation clear. Either way, it is one of the lesser British horror efforts of the era, and lacks the skill and sure hand Hammer would have brought to the game. Instead it reminds me of Tigon’s two horror films which added in an inept touch of science fiction: The Blood Beast Terror (1968) and The Creeping Flesh (1973).
Which isn’t really a good thing.