"The Blue Lotus" is the richest in substance of all Tintin books. It is based on real-life political events: The Japanese occupation of Manchuria in the 1930s and later invasion of China. Continuing from "Cigars of the Pharaoh," Tintin combats the opium trade. "The Blue Lotus" presents one of the most intricate plots of the series.
Herge's artwork here is also intricate - it is excellent. In addition to providing a great scenic backdrop, he captures so well all that is Chinese: people, clothing, buildings and residences, and Chinese designs and artwork. Herge had been introduced to a young Chinese sculpture student in Brussels who helped him portray Chinese culture and artwork. This is in stark contrast to the simple and stereotypical portrayals of things in "Tintin in the Congo" and "Tintin in America."
The consummately corrupt and evil Japanese operative Mitsuhirato is perhaps Herge's most compelling villain. Tintin measured against Mitsuhirato is the apotheosis of representations of good and evil in the Tintin series. Herge's portrayal of the Japanese was not well-received by them, but before Pearl Harbor he compensated for this to some degree in "The Crab with the Golden Claws." Note that Herge, the occasional social commentator, also takes a shot at Western arrogance in "The Blue Lotus."
Tintin's relationship with his friend Chang Chong-Chen and the other Chinese people in the secret society that combats the opium trade is very poignant. Within the series, it represents the most compelling display of teamwork: Tintin is heroic as always, but he also receives considerable heroic help. China is a huge country, as was its struggle against the occupying Japanese. Tintin's nobleness, courage, persistence, and emergence as a hero are uniquely grandiose and melodramatic in this story, clearly one of the best in the series. Quite interestingly, it is No. 18 on Le Monde's list of 100 Best Books of the Twentieth Century.