The Adventures of Jo, Zette and Jocko are the tales of a brother and sister and their pet monkey. Hergé created them on request from one of his French publishers but ultimately only produced five complete albums. Two of the albums, The 'Manitoba' No Reply and The Eruption of Karamako, have only had a limited English-language circulation in a double-volume that used the overall story title The Secret Ray and is now out of print. Some of the depictions in them are controversial and were thus passed over by first Methuen and then by Egmont.
The remaining three are in print today and will be looked at now. There's one two-part tale and one standalone adventure and these will be considered in the order in which they were originally published in French. This is different from the order the current Egmont editions list them, presumably reflecting the order in which they were first translated in the 1980s. The title characters are Jo and Zette Legrand, the children of a French engineer, and Jocko, their madcap pet monkey.
Mr. Pump's Legacy is the first part of the saga The Stratoship H.22, a title that actually appears on the cover and inside front page of this album. It tells of the circumstances that lead to the creation of the Stratoship plane itself and how Jo, Zette and Jocko come to fly away in it. Mr. Pump himself was an eccentric multi-millionaire obsessed with speed who left a large sum in his will for the first person to fly transatlantic at over 1000 km/h.
Destination New York is the second part of the saga and follows the children as they get list in the world and seek to fly the plane back to France then avoid further sabotage so that they can make the main flight before the will's provision expires and the money goes to Mr. Pump's nephews. It's a tale that ranges from desert islands to the Arctic, from beach resorts to New York.
The Valley of the Cobras is a standalone album, focusing upon the Maharaja of Gopal who commissions the children's father to build a bridge across the names valley, but others in the country fear the loss of their control of the trade routes so the children must handle a succession of saboteurs.
This series was created on request from Hergé's French publishers and it shows. The family are French, not Belgian, and there's a degree of compromised independence for the title characters by the anchor of the parents. By the time of The Valley of the Cobras Hergé seems heavily disinterested in the characters and the series, to the point that the Maharaja dominates the story. It doesn't help that the family isn't too well developed with the children somewhat generic characters, the mother a cipher and the father an engineer who seems to work in whatever field the story needs. Only the monkey Jocko has much of a distinct character but frequently he just provides humorous asides as he causes chaos, though in The Valley of the Cobras he proves observant enough to help at several key moments. There are no other recurring characters.
Also familiar from Hergé's other work is the presence of rich eccentrics who at times behave almost like children because their money allows it. Before his death Mr. Pump is shown to be so obsessed with speed that servants must wear roller skates, food is served on a conveyer belt and a system of raised chairs and slides allows speedy movement throughout the house. It is at the same highly efficient but also gives the home the atmosphere of a child's private adventure playground. Even more childish is the petulant Maharaja of Gopal who cannot take any personal setback at all, initially demanding that his manservant experience the same and the children be heavily punished. After a beating by the children's father the Maharaja has something of an epiphany and takes to them, but he continues to act like a child repeatedly, playing all over the place. It is easy to see why his subjects enjoy him going on holiday so much and dread his return.
Although this series began in the 1930s at a time when the Tintin adventures were focused on political satire, these tales feel very different from Hergé's better known series. As often happens with stories focused on such young children the pitch is distinctly young and as a result these albums aren't the most interesting for adults. It seems that Hergé himself agreed with this, primarily only producing the stories because of concerns raised about the Tintin adventures by one of his publishers and even within them he wasn't terribly invested in the characters, hence they come across as such bland ciphers. It's unsurprising that there are so few of these stories (although releasing translations of the other two albums in regular editions may not be the best move given the controversies and the low profile of the series). For what they are, straightforward children's adventures, they're not bad but they lack the sophistication to work on multiple levels and thus do not grow well with the audience.