

An architect, a security chief, a parapsychologist and an exorcist face evil in a Barcelona skyscraper.
Practical Effects
Pre-CGI death scenes that aged like fine cheese
Production
Actual Barcelona locations look expensive, rest doesn't
Acting
Michael Moriarty doing maximum Moriarty

Director
Freddie Francis
Trivia, insights & behind the scenes
Two directors credited because Freddie Francis quit mid-production; Ken Wiederhorn finished without reshoots.
One of several 'killer architecture' films post-Poltergeist, but the only one set in a genuinely beautiful real building (Torre de Valencia).