Its plot follows a lonely young man who kidnaps a female art student in London and holds her captive in the cellar of his rural farmhouse.

The novel is about a lonely young man, Frederick Clegg, who works as a clerk in a city hall and collects butterflies in his spare time.

Unable to make any normal contact, Clegg decides to add her to his "collection" of pretty, preserved objects, in the hope that if he keeps her captive long enough, she will grow to love him.

He promises to show her "every respect", pledging not to sexually molest her and to shower her with gifts and the comforts of home, on one condition: she can't leave the cellar.

Miranda reminisces over her previous life throughout this section of the novel; and many of her diary entries are written either to her sister or to a man named G.P., whom she respected and admired as an artist.

Literary scholars have noted the theme of class in the British caste system as a prominent point of interest in the novel.

"[4] Additionally, Cooper views the novel as a Gothic-inspired work presenting this class struggle "with an insistence on the tedium of Miranda's ordeal.

"[5] In the Journal of Modern Literature, scholar Shyamal Bagchee attests that the novel possesses an "ironic-absurdist view" and contains a significant number of events which are hinged purely on chance.

"[7] Bagchee notes the novel's greatest irony being that Miranda seals her own fate by continually being herself, and that through "each successive escape attempt she alienates and embitters Clegg the more.

"[10] Bagchee notes that the divided narrative structure of the novel—which first presents the perspective of Frederick, followed by that of Miranda (the latter divulged in epistolary form via scattered diary entries)—has the characters mirroring each other in a manner that is "richly ironic and reveals of a sombre and frightening view of life's hazards.

"[12] Scholar Katarina Držajić considers The Collector "one of the most prominent novels of the 20th century, [which] may be viewed from many interesting perspectives – as a psychological thriller, a Jungian study, a modern or postmodern piece of literature.

John Fowles is well established as a master of language, using a variety of tools to convey different meanings and bring his characters closer to his reader.

"[2] In 2014, Mary Andrews of The Guardian wrote that "Fowles invites us to defy his main character's excuses and read between the lines, and the facts paint a more chilling picture.

Fred doesn't accidentally abduct Miranda, there's a sense that he's been leading up to this event his whole life," and deemed Frederick Clegg "one of literature's most evil characters.

The novel was also loosely adapted by Filipino director Mike de Leon into a film titled Bilanggo sa Dilim (Prisoner in the Dark) in 1986.

[16] A stage adaptation by the actor Brian McDermott (writing as David Parker)[17] was first performed in 1971;[18] among its earliest productions was a West End presentation at the St Martin's Theatre in 1974, with Marianne Faithfull as Miranda and Simon Williams as Clegg.

[19] Another adaptation – written, again, by an actor: Mark Healy – was first performed at Derby Playhouse in October 1998,[20] later appearing at Sweden's Gothenburg English Studio Theatre in April 2007.

[21] Yet another adaptation, by Tim Dalgleish and Caz Tricks, was written for Bare Bones Theatre Company (of Wolverton, Milton Keynes) in 1997.