I won't go into the plot details as they have already been fairly well covered by the other posters.
By far the best part of this film is the perpetuation of the myth that LSD causes chromosome damage (a study based on flawed data was widely quoted in the media circa 1970-80, in fact, you still hear it from time to time). It held my attention to the end and the acting was actually pretty good.
It's supposed to be a cult classic, so I checked it out. I might even watch it again. There isn't a whole lot of suspense, but the premise is good and the score is really original.
Check it out if you get the chance.
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