After eight years, Hergé returned to Land of Black Gold, completing its serialisation in Belgium's Tintin magazine from September 1948 to February 1950, after which it was published in a collected volume by Casterman in 1950.

Set on the eve of a European war, the plot revolves around the attempts of young Belgian reporter Tintin to uncover a militant group responsible for sabotaging oil supplies in the Middle East.

Across Europe, car engines are spontaneously exploding; this coincides with the spectre of a potential war throughout the continent, resulting in Captain Haddock being mobilised into the navy.

Although detectives Thomson and Thompson initially suspect that the oil crisis is a scam intended to drive up business for a local roadside assistance company, Tintin learns from the managing director of Belgium's leading oil company, Speedol, that it is a result of someone tampering with the petrol at its source, and discovers a conspiracy involving a crew member of one of their petrol tankers, the Speedol Star.

Thomson and Thompson find the tablets and, mistaking them for aspirin due to their being packaged as such, swallow them, resulting in them growing long hair and beards that change colour.

", an iconic song by Charles Trenet, appears in parody as the roadside assistance company's advertising jingle, which plays on Thomson and Thompson's car radio at the very beginning of the story.

[14] The Supermarine Spitfire, a British single-seat fighter aircraft, was used as the model for Kalish Ezab's plane which drops leaflets onto Bab El Ehr's camp.

[24] Hergé was planning on creating a story in which Tintin travels to the moon, but his wife Germaine and close friend Marcel Dehaye both advised him to revive Land of Black Gold instead, recognising that it would entail less work and thus cause him less stress.

[21] He nevertheless made revisions to the early part of the story, namely by reworking the characters of Captain Haddock (who now first appears in a new scene on page 3) and Professor Calculus, as well as the location of Marlinspike Hall, into the narrative, all of which were elements that had been introduced to the Adventures of Tintin during the intervening eight years.

[30] His co-workers and staff at Tintin magazine were increasingly annoyed by unplanned absences such as this, which affected the entire production; his colleague Edgar P. Jacobs sent him letters urging him to return to work.

[35] For this version, Hergé transplanted the events of the story from Palestine to the fictional Emirate of Khemed and its capital city of Wadesdah, a setting that he had used in a later adventure, The Red Sea Sharks.

In this revised version, Tintin arrives at Khemkhah in Khemed, where he is arrested by the Arab military police before being captured and taken directly to Bab El Ehr.

[37] As a result of the truncation of Tintin's kidnapping, which now occurs two pages earlier than in the second version, the Thompsons' crash into a palm tree in the desert now takes place after the aforementioned scene.

[13] Background details was changed accordingly, with Jewish shop fronts with Hebrew signage being removed,[38] and the nonsensical pseudo-Arabic script from the earlier versions was replaced with real Arabic text.

[13] Hergé biographer Benoît Peeters stated that "no book has gone through more ups and downs" than Land of Black Gold,[40] adding that it carries a "mood of foreboding" caused by the impending war in the story.

[27] Despite its problems, they thought that the Thom(p)sons' ingestion of Formula 14 was "virtually inspired", showing that Hergé "had lost none of his touch when it comes to creating unforgettable images".

[6] Harry Thompson described Land of Black Gold as a "patchwork effort", believing that the final result owed little to the "story's original satirical thrust".

[47] Believing that it offered a "fine swansong" for the decline of the Thom(p)sons as central characters in the series,[48] ultimately Thompson felt that Land of Black Gold retained a "somewhat fragmentary air".

[49] Differing from Thompson's assessment, Hergé biographer Pierre Assouline felt that the inclusion of Haddock into the story was successful, "precisely because [it] defied all logic".

[50] Literary critic Tom McCarthy believed that in the story, the desert represented "a space of multiple misreading", which included the mirages, fake documents, and cases of mistaken identity.

[52] Describing the scenario in which Thomson and Thompson are lost and driving around the desert, he refers to it as a "brilliantly allegorical scene",[52] before highlighting Hergé's "wishful retroactive wiping out of history" by evading the war.

[53] In his psychoanalytical study of the Adventures of Tintin, the literary critic Jean-Marie Apostolidès dealt only briefly with Land of Black Gold, commenting that Calculus' development of a cure for the Thom(p)sons' consumption of N14 was a sign of his growing status and reputation as a scientist, as he moved from being the "small-time, ridiculous" inventor of Red Rackham's Treasure and came to establish himself as the internationally renowned scientist of Destination Moon.