The film features an ensemble cast that includes Henry Cavill, Bryce Dallas Howard, Sam Rockwell, Bryan Cranston, Catherine O'Hara, Dua Lipa, Ariana DeBose, John Cena, and Samuel L. Jackson.

Argylle is a standalone spin-off from the Kingsman franchise, with a crossover between the two planned as part of an intended spy-focused shared universe from Vaughn.

On a train journey to visit Ruth and her father, Barry, Elly is saved from an ambush by an actual spy, Aidan Wilde, who explains that a devious organization known as the Division has targeted her because her novels seemingly predict their future.

Escaping to France, Aidan and former CIA deputy director Alfred "Alfie" Solomon reveal that Argylle is not entirely fictional: Elly is, in fact, agent Rachel Kylle ("Argylle" seemingly having been derived from "R. Kylle"), who was captured and brainwashed by the Division five years earlier and made to believe that Dr. Margaret Vogeler (Ruth) and Director Ritter (Barry) were her parents.

Elly put her suppressed memories, in modified form, into her novels; Aidan resurfaces as one of her characters, Wyatt, while Alfie reappears as her cat.

Ritter reveals that Rachel was, in actuality, a double agent and one of their most loyal assets for the Division, after which she offers to interrogate and subsequently shoots Aidan.

Aidan and Rachel escape to the Division facility exterior, revealed to be a cargo ship, to use the satellite connection to send the Masterkey.

In a mid-credits scene, taking place twenty years earlier, a young Argylle is revealed to be a Kingsman agent, with the first novel being based on his life.

Also appearing in the film are Rob Delaney as Deputy Director Powell; Jing Lusi as Li Na, a love interest of Argylle;[8][9] and Tomás Paredes as Carlos, a field agent of the Division.

[25] Elly Conway, later revealed as the fictional author of the in-universe Argylle novels, was initially reported to have written the book that the script was based on during the film's announcement.

[4] The claim was questioned by The Hollywood Reporter in September 2022, as they were unable to verify Conway's existence and their attempts to contact her, her publicist, and her talent agent were unsuccessful.

The website's consensus reads: "Argylle gets some mileage out of its silly, energetic spin on the spy thriller, but ultimately wears out its welcome with a convoluted plot and overlong runtime.

[33][46] Forbes's Erik Kain noted that, in general, reviews criticized the film's length, number of plot twists, and use of CGI in action sequences, labeling it a parody of the genre.

[47] Brennan Klein of Screen Rant summarized the reviews as mixed, noting the polarized reception of the "meta" elements, while the cast received praise.

[48] Peter Bradshaw of The Guardian gave the film one star out of five and called it an "unbearably self-satisfied smirk of a spy caper from Matthew Vaughn";[49] various other reviews were also very negative.

[50] Jackson Weaver of CBC News conceded that the "movie's meta-backstory is much more interesting than its actual storyline, by a lot",[51] while the Los Angeles Times's Katie Walsh, also quite critical of the film, mentioned its "amusing premise" and enjoyed Rockwell's presence.

[58] In February 2024, Vaughn confirmed that the prequel installment is being developed with Louis Partridge starring as Argylle (as portrayed by Cavill) in his formative years.