The film stars Judy Geeson as a psychologically-fragile woman who, upon relocating to a rural boarding school where her husband has taken a job, finds herself being tormented by a mysterious figure with a prosthetic arm.

[3] Peggy, an unassuming twenty-two-year-old caregiver, has recently married Robert Heller and is scheduled to move with him to a secluded boys' boarding school south of London for his work.

Robert explains to Peggy that he had met Michael when he was working in a hospital as a medical student; the boarding school had nearly burned to the ground in an accident years prior, and, devastated, Michael returned to the property, setting up recordings of boys' laughter and classroom lectures over the building's intercoms to re-create the feeling of the school's former glory days.

Robert storms out of the school with Peggy and attempts to hang her from the tree outside in a staged suicide but is suddenly grabbed in a strangle grip by Michael.

One of the police officers tells her that the school has been shut down for years, but suddenly, the sound of a boys' choir begins emanating from the building.

Fear in the Night derived from a script written by Jimmy Sangster called Brainstorm that was originally developed for Universal Pictures in 1963.

[8] Fear in the Night was released in the United Kingdom on 9 July 1972, shown as a double bill with Straight on Till Morning, another Hammer film with similar themes.

"[9] Executive Michael Carreras at Hammer studios conceived the pairing as a marketing tool, stating: "My original concept was to have two properties by the same author on a central theme, being made into two films both directed by the same person.

[10] Time Out called the film "one of those neatly constructed but slightly mechanical psycho-thrillers which make you feel as if someone is pushing buttons connected to electrodes in your brain", but that "Hammer fans will soon recognise the plot as a thinly disguised reworking of A Taste of Fear (sic)".

[13] Popcorn Pictures gave the film a middling review, calling it "a brave attempt by Hammer to go in a new direction but ultimately fails because even in 1972, the plot twists weren’t new or original in the slightest.

[16] It was released for the first time on DVD in North America on 8 October 2002 by Anchor Bay Entertainment as part of their "Hammer Collection" series.

[20] Literary critic John Kenneth Muir has noted Fear in the Night as a mood piece, as well as an example of the gendered fictional representations of "damsels in distress," a motif that was recurrent in horror films of the era, including amongst Hammer Studios' films itself— Straight on Till Morning, which Fear in the Night was paired with upon its British theatrical release, contains similar themes of female hysteria.

"[24] Huckvale also draws comparisons on the character of Molly Carmichael (Joan Collins) as a catalyst to Peggy's purported hysteria, likening her to the unnamed wife of Maximilian de Winter in Daphne du Maurier's Rebecca.

"[The character] of Peggy marries a man she knows little about and then finds herself transplanted into a grand house with its own intimidating rituals, but with the major difference that the Rebecca figure is still there in the form of Joan Collins' Molly Carmichael," Huckvale says.

Thus, when Carmichael unties Peggy's hair band, we are intended to interpret the act as a form of sublimated rape— at least that is the implication at this stage in the plot.

It also gives Sangster an opportunity to reveal Carmichael's prosthetic arm, which he threateningly clicks into position to hold one end of the ribbon while he unties the knot with his other hand.