This book sees a return to the more overt political themes of the series, making a very direct attack on the Japanese invasion of China by depicting a fictionalised version of the events that began it. Although the location is shifted to closer to Shanghai, the story pulls no punches in showing a Japanese agent staging an incident by blowing up a railway, followed by Japanese officials distorting the details of a small piece of sabotage into a brutal attack on innocent passengers so as to whip up sentiment and invade China under the pretext of maintaining law and order to protect Japanese interests there. This goes much further in accusing Japan of acting under false pretences than the official League of Nations report at the time and it's unsurprising that diplomats complained, although they can't have been too enthusiastic to start proceedings for libel that would have hinged on the facts of the Mukden Incident.
In earlier stories Hergé had taken Tintin to idealised places that owed more to popular culture and propaganda than reality. Taking Tintin to China in pursuit of drugs smugglers could have followed the same course and resulted in a dark country that literally throws away its babies whilst power is held by cunning schemers of the Fu Manchu type. But instead these stereotypes are reserved for a sequence where Tintin explains to the young boy Chang how ignorance of foreign people is common around the world and that Europeans have these bizarre ideas about what the Chinese are really like. It's notable that the only characters to go around dressed like Fu with pigtails are Thompson and Thomson, and it's the first time their disguises are absurd and lead to widespread ridicule.
Otherwise this is a highly sympathetic and properly researched portrayal of China with attacks on casual racism, seen most vividly in an early scene where Tintin's rickshaw driver accidentally bumps into Gibbons, a Western man who responds by attacking with his stick and shouting "Dirty little Chinaman!" Later in the "Occidental [Western] Private Club" Gibbons talks of the need to "civilise the savages" and of "all the benefits of our superb western civilisation" whilst knocking a tray out of a waiter's hands and then attacking him for it. Tintin's reaction upon their initial meeting and the whole portrayal of the club scene leave us in no doubt just who is in the wrong. Coming so soon after Tintin in the Congo it's a surprising shift in attitude by Hergé. And it's notable that just about all of the villains in the story are non-Chinese, again stepping away from the easy path and showing a decidedly dark approach to westerners in China. But whilst his portrayal of the Chinese is commendable, that of the Japanese is far more clichéd, with their visual depiction especially poor. There are no sympathetic Japanese characters at all, or indeed any non-Chinese bar Tintin himself, Snowy and the Thom(p)sons. It seems that further development would be required.
The plot is relatively straightforward but spread across the whole story, picking up on strands from Cigars of the Pharaoh as Tintin follows clues about the opium smugglers and the madness poison from India all the way to Shanghai, where he discovers the activities of the Japanese businessman and agent, Mitsuhirato. (The "Blue Lotus" of the title is the name of an opium den when Tintin spies on Mitsuhirato and later has a final confrontation with the villains in the cellar.) The real mastermind behind the opium cartel is revealed, as is the fact that he survived his seeming death at the end of the previous album, but it feels rather forced as his only previous mention in this album is when Tintin hides in a cinema and sees his foe's output on the screen. There's clearly an attempt to give Tintin a recurring foe but it would be many years before this would be followed up.
Another character who would return many years later to make a greater impact is Chang Chong-Chen, a young boy who is rescued from a flood by Tintin. The two instantly strike up a friendship and Chang helps Tintin throughout the last third of the story. Indeed, throughout the tale Tintin repeatedly finds his actions win him allies when he least expects it, whether the milkman who helps him get past a military cordon because the rickshaw driver is his brother or the Sons of the Dragon, a secret society who defy expectations by working against the opium trade, wanting to free China of the devastating effects the drug is having. Wang Chen-Yee, the society's head, provides repeated assistance to Tintin throughout the tale and at the end Tintin is able to reward all his allies as Wang adopts Chang.
Ultimately this album shows a far more sophisticated portrayal of a different land than before and avoiding the clumsy easy stereotypes. The plot is simple but strong whilst the characters mostly work as strong rounded beings. The portrayal of the Japanese is not the best, though given the time the story was originally published it's easy to see why such a harsh light was shown on them. Overall this is definitely the best of the Adventures so far.