The very notion of Michael Winner tackling post-The Exorcist (1973) Satanic horror should sound alarm bells. Winner was never the most subtle of directors and restraint or understatement were never going to factor highly in his concerns while unleashing the forces of hell onto disco-era New York. The Sentinel is based on an equally unsubtle novel, published the year after the film version of The Exorcist made all things demonic fashionable, by Jeffrey Konvitz, co-writer of Silent Night, Bloody Night (1972), who also co-wrote the screenplay of The Sentinel with Winner. It’s equal parts The Exorcist, Rosemary’s Baby (1968) and The Omen (1976) but not as good as any of them.

New York fashion model Alison Parker (Cristina Raines) has a successful career but is deeply troubled, having attempted suicide a number of times. She moves into an old apartment block in Brooklyn Heights that she rents from Miss Logan (Ava Gardner). The top floor of the building is occupied by a reclusive blind priest, Father Halliran (John Carradine), who spends his time sitting in his window. Alison is soon becoming physically ill, passing out and suffering from insomnia, and begins to hear strange noises from the apartment above her. Her neighbours are a rum lot, including the eccentric Charles Chazen (Burgess Meredith) and the lesbian couple Gerde (Sylvia Miles) and Sandra (Beverly D’Angelo), though when she mentions them to Miss Logan, she’s told that apart from Halliran, she’s the only tenant in the building. Alison’s lawyer boyfriend Michael (an almost unrecognisable Chris Sarandon) comes to suspect that she’s suffering delusions and hires corrupt detective Brenner (Hank Garrett) to investigate. Alison begins to hallucinate seeing her late, abusive father (Fred Stuthman) haunting the building and she ends up being admitted to hospital suffering a breakdown. While the police fail to get to the bottom of things, Alison learns from Halliran that the apartment block is the gateway to Hell, that he’s the eponymous sentinel left to watch over it and that she’s been marked as his replacement…

Universal’s money provided Winner with enough resources to pull together an interesting cast who at least manage to not to look too embarrassed by how ridiculous it all is. Among the supporting cast we find Jeff Goldblum as a photographer (conspicuously dubbed in all but one of his scenes), Tom Berenger, William Hickey, Nana Visitor and Christopher Walken among others early in their career. Richard Dreyfus turns up in one blink-and-you’ll-miss-him cameo as a man talking to a woman on the street outside the apartment block. Eli Wallach is also on hand as one of the investigating cops, but his eccentric performance is not, perhaps, one that he would have looked back on with much fondness.

Spotting the familiar or soon-to-be-familiar faces is one of the joys of the film, and there are others. The first half of the film has a fairly decent mystery, and all the haunted house business is reasonably engrossing. But Winner’s ham-fisted direction batters all that into submission as the film slowly transforms into something wackier and bloodier. Beverly D’Angelo masturbating in front of Raines, whose reaction seems oddly wrong, is one of the film’s many oddities and it’s far from the most tasteless moment. Expecting taste from horror films, particularly exploitative ones directed by Michael Winner, is a fool’s game but for many, he oversteps the mark completely in the film’s otherwise delirious climax. As Chazen, effectively revealed as the Devil himself (Meredith had played His Satanic Majesty once before, in the Amicus anthology film Torture Garden (1967)), opens the doorway to hell, it lets loose a shuffling army of demons played by people with real deformities that Winner found by scouring hospitals and sideshows. “They loved it,” Winner later said attempting to justify the casting. “When the film opened in their hometowns they sent me press cuttings.”

Elsewhere, the are more traditional shock effects courtesy of Dick Smith – Michael’s death and Alison’s stabbing of her zombie father are particularly grisly and although the final shot of a now blind and prematurely aged Alison fails to convince, the make-up applied to Carradine is very effective. Of course, Winner applies these shocks with all the finesse of a man smacking you in the face with a sledgehammer, but in their own cheap shot way, they work well. A few years later, Lucio Fulci came along to show how extreme splatter could be spliced to moody atmospherics with his own “doorway to hell” films, Paura nella città dei morti viventi/City of the Living Dead/The Gates of Hell (1980) and …E tu vivrai nel terrore! L’aldilà/The Beyond/7 Doors of Death (1981), both films that might owe something to The Sentinel but which are superior in every way.

One might, perhaps, tease a few nuances from the script regarding Catholic guilt, redemption, sin and so on, but that’s probably giving it all far too much credit. In his book Hollywood from Vietnam to Reagan and Beyond, Robin Wood called it “the worst – because most offensive and repressive – horror film of the 70s” which is probably over-egging it a bit (he clearly hadn’t seen some of the celluloid effluence congealing in some corners of 70s horror) but it’s certainly not by any means a great film. The first half has promise, but it required a more interesting and refined director than the man that Winner had devolved into by the 1970s to make it work. Winner piles on the tastelessness and hammer blow shock effects, and yet somehow manages to still make it a very dull experience.

In 1979, Konvitz published a sequel to his original  book, titled The Guardian. Despite a plethora of films of that name, including a 1990 horror film by The Exorcist director William Friedkin, none of them were adaptations of Konvitz’s work.