A woman is drawn to an island which is inhabited by nuns with a secret. Soon people are dying and no one can speak clearly even though the film is dubbed so you only get the barest ideas of what the **** is going on! Probably has something to do with the monster in the basement that looks like it is related to the Cyclops from Contamination!
https://www.imdb.com/title/tt0109550/?ref_=nv_sr_srsg_6