In a café in the country town of Huxley, Australia, Ernest reads that Laurence Birch, the actor cast to play him in a television adaptation of his books, has died after being struck by a delivery van. Ernest is with his fiancée Juliette, and they are rehearsing for a loan meeting at Huxley’s Bank. Outside, a massive migration of small white moth-like butterflies darkens the sky.

Ernest recalls that Birch, a method actor, had copied his clothes and stolen his coffee loyalty card, even writing “Ernest” on his takeaway cup. Leaving the café, Ernest is bumped by a stressed man whose wristwatch is set four hours behind—the start, he notes, of Bryce Fredericks’s bad day.

Ernest and Juliette cross the street to Huxley’s Bank through the butterfly swarm. Ernest describes the town’s gold-rush origins and the imposing sandstone building founded by Harold Huxley. In the atrium, a large gold nugget labeled “Harold Huxley’s First Find, 1892” sits on a podium (21), watched by Felix, a security guard whose pants seem too heavy for his frame. From receptionist Michelle’s travel-photo screensaver and healing wrist brace, Ernest deduces that she has just returned from a long vacation, and he notices flirtatious looks between her and Felix.

Now, Ernest hints that of the 10 thieves, all but two are already inside the bank (Felix among them), and three full heists are underway.

In his office, Winston Huxley, an elderly bank director in an oddly oversized peach shirt, reveals that he summoned Ernest not to discuss a loan but to hire him. He requires them both to sign a non-disclosure agreement. They sign with Winston’s gold pen, cast from a piece of his grandfather’s nugget.

Winston then explains that his brother and co-director Edward has been missing since Wednesday. Before he disappeared, he changed the vault code and left the bank unable to access its cash; he refuses to involve the police or discuss Edward’s son Ben, killed in an accident the prior year. In Edward’s office, Winston discovered a bundle of $10,000, which had a dye pack, explaining Winston’s borrowed shirt—an exploding ink pack had ruined his own. Winston offers to fund Ernest’s detective agency if he finds Edward and reopens the vault.

Ernest and Juliette return to the atrium, where they overhear an argument between bank teller Milton and Remy Allard, the producer who optioned Ernest’s book for television. Milton refuses to serve Remy due to an urgent matter.

When Remy sees Ernest, he claims he is in Australia for nearby filming and banks at Huxley’s only for his clothing company, but Ernest suspects that he is lying about his reasons for being at this remote branch. Remy dismisses Birch’s death as a production inconvenience and mentions that Birch was heavily insured, though not as heavily as some. That slip about insurance, combined with Remy’s unexplained presence in the same building where Edward has vanished, and the vault is locked, leads Ernest to wonder whether Birch’s death, Remy’s arrival, and Edward’s disappearance share a common cause.

Ernest and Juliette meet Father Gabriel, a young priest waiting in the atrium with them. He is observing a vow of silence and communicates by typing on an iPad. Gabriel tells them that he administered last rites to Birch at dawn and shows them an eBay seller auctioning Birch memorabilia, including the coffee cup marked “Ernest” that Birch was holding when struck.

Ernest realizes he has accidentally pocketed Winston’s gold pen, and Juliette jokes that he has just robbed a bank. The moment is cut short when Remy grabs the shoulder of the hooded customer at Milton’s window and spins the figure around, revealing a gun. A shot rings out as Ernest realizes another robbery is already underway.