How is it that “All of Us Strangers,” this strange little gay fable from “The Twilight Zone,” is on the receiving end of such rapturous reviews from some critics, many of them on the festival circuit? It may be because the film co-stars Irish actor and critics’ darling Paul Mescal (“Aftersun”), who is currently filming “Gladiator 2,”and features an admittedly wrenching performance from Irishman Andrew Scott, perhaps best known as Professor Moriarty in that almost-good Benedict Cumberbatch “Sherlock” series and as “Fleabag”’s “hot priest.”

Directed and co-written by Andrew Haigh (“45 Years”) based on the 1988 novel “Strangers” by Japanese author Taichi Yamada, the film is an odd bird. Haigh added the gay element. Scott is Adam, a single gay screenwriter who never gets past a few opening words of his latest screenplay. He is interrupted by a knock at the door. It is Harry, (Mescal), a handsome gay neighbor with a bottle of Scotch and a flirtatious manner. Will Adam invite stranger Harry in? Not yet. Both men live in the same faceless high-rise on the outskirts of London.

To say that the plot of “All of Us Strangers” is contrived is to state the obvious. After a train ride, Adam visits his empty childhood home, where he finds the ghosts of his parents who died in a car accident when he was 12 and are now younger than he is. His mother is played by Claire Foy of “The Crown” and his father is none other than the eponymous “Billy Elliot” (2000). Can we refer to Adam’s parents (and the film itself) as Ghosts of Performances Past?

“All of Us Strangers” takes the idea of being reunited with our dearly departed and combines it with scenes at a crowded gay bar and a ketamine binge. It’s “It’s a Wonderful Life” with hallucinatory anesthetics, a ghostly former Queen, a ghostly former boy dancer and a gay romance. Adam comes out to his parents with different results. His beautiful Mum, identified only as “Mum,” accepts Adam for who he is. His gruff “Dad” is less understanding. Adam holds a grudge against his father for not finding out why the boy came home from school, went to his room and wept almost every day. It was because of bullying. Perhaps, unsophisticated Dad didn’t know what to do.

“All of Us Strangers” is sentimental and angry, and I suspect that Haigh knows exactly what he is doing, although a scene in which Adam gets in bed with his parents in his childhood jammies is truly over the top. In Yamada’s novel, the ghosts are evil, secretly sucking the life out of its protagonist. Haigh’s haints are more benevolent. But watching “All of Us Strangers,” I felt like Haigh was sucking the life out of me in an effort to wring a tear from my eye. Stop, please.

(“All of Us Strangers” contains profanity, drug use and sexually suggestive scenes)

“All of Us Strangers”

Rated R. At the Coolidge Corner Theater and Landmark Kendall Square. Grade: B-