Trouble soon appears, much to the chagrin of little old lady Mrs Haggerty (Louise Closser Hale), when government troops halt the express. Everyone is thrown out, to have their passports examined, right in the middle of dinner. Eric Baum (Gustav von Seyffertitz), a cantankerous invalid, certainly isn't happy with the effect that the cold air could have on his constitution, ignoring the fact that they might never reach Shanghai alive. However, a spy is soon arrested and the train goes on its way, but not before Chang manages to send a telegraph message. It turns out that not only is he sending a warning to the rebel forces but that he is their Commander, and he's travelling right under the noses of the government forces. Under his specific instructions the train is to be stopped again further down the line, by the rebels this time. Before this occurs we learn more of the passengers, such as the fact that Lily and Doc (Capt. Harvey) have a "past"; they were once engaged to be married.
When the locomotive once again grinds to a halt, the situation seems altogether more uncertain. The rebel troops are a lot more jumpy, undisciplined and liable to mete out arbitrary punishment. That most of characters are foreign seems to help, although Chang soon shows his uncompromising (almost vicious) side and this seems like scant protection. Since the captured spy was Chang's right-hand man he's looking for an important hostage, as material for a straight swap. Capt. Harvey fits the description, since he's to perform a critical operation on the British Governor in Shanghai, and Chang arranges matters. Meanwhile the ruthless leader has his eye on both Lily and Fei, fancying a little feminine company, although neither of the ladies are interested. The exchange is arranged, to the relief of the passengers, but there are additional complications. Lily still loves Doc, and vice versa, but they're too stubborn to admit it, while Chang wants Lily and doesn't mind putting Doc out of the picture to get her.
Despite showing its age, via the attitudes and modes of behaviour, Shanghai Express is a movie with great heart. Dietrich is stunning as usual, and captivatingly photographed, but also acts well too, combining the worldly-wise lady with the naive, loving girl to perfection. This is a story of character, exploring the intrigues of sex, love and power in the confines of a railway car (mostly) and exposing hypocrisy. From another angle, this is a tale of strangers discovering their shared interests and working together towards triumph, ending up as friends. Whichever viewpoint you take, the story contains a lot of fine acting which goes a long way to giving everyone some depth, despite the slightness of certain roles. It's all rather enjoyable, in a camp way, and surprisingly exciting. Well worth seeking out.