The 24th and final Tintin adventure, unfinished due to an unfortunate case of Author Existence Failure.An art craze sweeps over Europe - everyone is suddenly obsessed with Alph-Art, or statues of letters. Even the Captain buys an H, but Tintin remains skeptical of the movement. He looks into Alph-Art's origins, and finds his usual mess of crooks and swindlers (including Sakharine, Mr. Gibbons, Mr. Trickler, and Emir Ben Kalish Ezab) using Alph-Art as a cover for forgeries. However, he is eventually caught, and Herge's last panel shows Tintin being marched away, to be covered with plasticine and sold off as a statue.
- Arab Oil Sheikh: Emir Ben Kalish Ezab uses his oil profits to negotiate the purchase of Windsor Castle and Centre Georges Pompidou, respectively landmarks of the United Kingdom and France.
- Art Shift: Unintentional, seeing that most of the story are loose drawings and sketches, intended to be redrawn later.
- Continuation: Has a few, but the best-known one is Yves Rodier's version, which has the feel of a Grand Finale, ending with Rastapopulos's on-screen death and Martine getting Promoted to Love Interest.
- Deliberately Monochrome: Averted. The story is in black-and-white, because it's presented in unpublished form.
- Drink Order: Captain Haddock usually goes for Loch Lomond whiskey. In this story, Haddock can no longer drink due to the lingering effects of a pill used on him by Calculus. The withdrawal is causing him various problems and a change in lifestyle.
- Hijacked by Ganon: Tintin notes a few times that Endaddine Akass' voice sounds familiar. Following some draft of the author, it was about to be revealed that Akass is none other that Rastapopoulos who performed Magic Plastic Surgery. However what happened to him after Flight 714 is a mystery.
- Left Hanging:
- The story ends with Tintin captured by a mysterious enemy. He's scheduled to be killed by getting liquid polyester poured on him... with no resolution.
- Mad Artist: The story would have had Tintin encountering the modern art scene and becoming the focal point of one of these.
- Nightmare Sequence: Haddock has a nightmare involving Bianca Castafiore. At first it simply involves Bianca forcing him to drink 'his medicine". Said medicine is whisky, which Haddock can no longer drink without ill effects. He tries to resist and Bianca turns into a giant bird-like creature. She attacks him and the dream sequence ends.
- Punny Name: Endaddine Akkas's name is a pun of the Marol dialect expression En dat in àà kas! (And that in your chest!, said when telling someone off). Marol is a dialect spoken by Flemish people in Brussels.
- Real Life Writes the Plot:
- Endaddine Akkas was based on the French art forger Fernand Legros.
- Ramo Nash was modelled on Elmyr de Hory.