What leaps out above all else in this story is the sheer number of returning characters from previous stories, introducing many new ties amongst them. So at the start Tintin and Captain Haddock meet General Alcazar, originally from The Broken Ear and once more in exile but in the process of purchasing weapons from none other than Dawson, previously the police chief in the International Settlement in Shanghai back in The Blue Lotus but now an arms dealer. He is also selling to Bab El Ehr, the ambitious sheikh previous seen in Land of Black Gold. Also appearing from that story is Abdullah, who has been sent to Marlinspike for his protection (if not the residents'!), and his father, the Emir Ben Kalish Ezab who has been overthrown. In the hope of escaping Abdullah's tricks Tintin, Snowy and Haddock journey to Khemed where they receive help from Oliveira de Figueira, originally seen in Cigars of the Pharaohs, then are attacked by forces sent by the officer "Mull Pasha", who is actually Dr. Muller, again from Land of Black Gold. They soon discover there is a trade in slaves, with the key ship being commanded by Allan, originally seen in The Crab with the Golden Claws, though retroactively added to Cigars of the Pharaohs when that story was redrawn. Over on a pleasure liner is none other than Bianca Castafiore, first seen in King Ottokar's Sceptre. At the head of it all is the businessman the "Marquis di Gorgonzola" who is revealed to be Rastapopoulos, again first seen in Cigars of the Pharaohs. Returning to Marlinspike, Tintin and Haddock discover that the nuisance of Abdullah has gone, only to be replaced by a nuisance from The Calculus Affair, Jolyon Wagg.
This is by far the largest number of return appearances yet seen and it's little surprise that Thompson and Thomson, Nestor and Calculus are used sparingly, primarily to deliver key information to Tintin and then suffer the antics of Abdullah. But the result is a tale that almost meanders from returning character to returning character without really stopping to explain the logic of it all. Even the level of coincidence is addressed right on the first page as Tintin and Haddock discuss plot holes in a film they've just seen and the absurdity of how they could just bump into someone like Alcazar, only to do just that. Whilst some of the characters have been previously shown to have links to Khemed or to be well travelled, others are repurposed in order to fit the needs of the story. At the heart of it is Rastapopoulos, clearly being built up to be Tintin's archenemy to the point that he's shown to actually escape at the end under cover of seemingly drowning. Though the Adventures have reused elements before, even elevating one-off characters into recurring parts, it is with this story that takes the key leap into an integrated fictional universe. But in trying to make the stories seem grander for these ties, the universe as a whole becomes so much smaller and it becomes harder to go anywhere without falling over familiar faces. It can also create problems in languages where the Adventures were translated either incompletely or out of order.
Because of this overloading, the plot of the story is so messy that this is almost a return to the random wanderings of the earliest Adventures. At the start of the story it seems the main focus will be on General Alcazar's plans to regain power and the weapons he's purchased for the task. But this is quickly forgotten and instead Tintin decides to go to Khemed in the hope of freeing the Emir and getting Abdullah off their hands. Once there the story eventually finds the Emir, but rather than focusing upon attempts to restore him the story instead turns to trying to expose the slave trade and bring down "di Gorgonzola". Although the latter has been supporting Bab El Ehr, this doesn't particularly feel like a mission to remove a key ally but instead a sign of just how all over the place the story is. Such are the twists that the eventual restoration is covered by a collection of newspaper clippings confirming also the capture of most of the other villains. The title of this book reflects the problems as only one actual shark is seen and the term is only sparingly applied to the slave traders. The original "Coke on board" isn't much better. It may follow the tradition of Cigars of the Pharaohs and The Crab with the Golden Claws in being named after the disguise for what is being smuggled, but the term comes very late in the day and confuses more than it enlightens. Also evoking the early days, but doing so successfully, is a resort to a series of coincidences saving Tintin instead of relying on his wits. So when a bomb is place on a plane, instead of Snowy successfully raising the alarm a separate engine fire brings the plane down in time to escape. Whilst riding across the desert our heroes are attacked by armoured cars and planes sent by Mull Pasha, only for the planes to misunderstand their orders and destroy the armoured cars before flying away. A diver is sent to plant a depth charge to sink the ship Ramona, but gets hit by the lowering of the anchor and a shark swallows the charge. This story is trying too hard to recreate the feel of the early days and it flounders as a result.
Also reflecting the early days of the series is the appalling depiction of African characters. As noted above, Hergé did modify their dialogue for later editions but the current edition on sale in English appears to be a translation of the earlier edition. On board the ship Ramona, Tintin and Haddock discover the "cargo" are in fact men from Senegal and Sudan who believe they are making the Hajj - a pilgrimage to Mecca - but have been tricked by the crew and are in fact being taken to be sold as slaves. Speaking pidgin English and taking a long time to understand what Haddock is explaining to them, they do not come across as devout worshippers determined to get to Mecca in spite of all the dangers but rather as simple minded children who only finally understand when one of the eldest amongst them recalls the previous disappearance of men from his village. There's also an almost casual attitude to the whole business, with the Emir mentioning the trade in passing merely as something he threatened to blackmail di Gorgonzola's company Arabair with, and when Tintin and Haddock discover the men are on board they are slow to release them from the hold, being more concerned with the radio and Skut, a pilot from Estonia shot down by Tintin who rapidly switches sides. The contrast between the depiction and treatment of Skut and the nameless Muslims could not be starker. Haddock even calls the latter "Coconuts" in his outbursts. Hergé may have been inspired to draw attention to the modern-day existence of slavery, but over a quarter of a century on from Tintin in the Congo he was still presenting an assertion of European racial superiority. He may have tried to correct the mistake subsequently, but that correction does not appear to be the one currently available.
This story is effectively an anniversary reunion special, albeit without an actual anniversary during the original publication, bringing back many characters, settings and ideas from earlier tales. Unfortunately, it brings too much back and the result is a deluge of characters that force the story to twist and turn in order to accommodate them at the expense of a clear narrative, whilst the appalling depictions of Africans are something that most definitely did not need to be revisited. The weight of all this makes this a rather disappointing album.