German critics were apparently dismissive of this, Fritz Lang's third feature film (and first surviving one), deriding as sensationalism and nothing more. I don't disagree, but I also don't really see much wrong with it. The narrative and thematic ambitions are modest, focused more on purely entertaining spectacle rather than self-conscious art, but there's nothing wrong with that. It's not the most successful entertainment of the silent period or anything, but it functions well enough.
Kay Hoog (Carl de Vogt) is a sportsman living in San Francisco when he discovers a message in a bottle bobbing about at sea. The message describes a treasure trove of ancient gold hidden in the caves under a lost population of Incans in South America. He openly describes, reads, and shows the letter at his sailing club in front of Lio Sha (Ressel Orla), a secret operative of the criminal enterprise known as The Spiders. With the knowledge of the treasure and the message that contains some direction, she takes the information back to the Spiders' secret headquarters (including a 1919 version of a television she uses to listen in on the conversation that doesn't include her), and they decide to go after the message and the gold.
They attack and rob Hoog in the middle of the night (leaving him alive so the movie can happen), and the chase is on. Hoog takes the train down to the southern reaches of Mexico where he meets up with a scientist who works on weather balloons that he plans on hitching a ride with to get him over the mountains and to the Incan city as fast as possible. He has to steal back that message from the bottle first (for reasons? For action-adventure reasons). He faces down Lio Sha and her newly hired of bandits in a tense and exciting little exchange where he gets the paper, escapes through the roof, leads a horse chase to the scientist about to take off in the balloon where Kay jumps onto the final rope and climbs all the way up. You know...silent stunts are awesome because they were so wildly irresponsible.
Kay gets to the Incan city first, and the Incan city is really the showstopper of the film. It's a relatively small set (especially in comparison to the sets that Lang would build for Metropolis a few years later), but they are wonderfully densely designed and detailed that Lang fills with actors, giving it a dense, lived-in quality. The first person Kay meets, though, is the Incan princess Naela (Lil Dagover). Both protected from the regular human sacrifices the Incans make and also being groomed as an executioner by her father. The Incans capture Lio Sha when her party camps nearby, and Naela is trying to protect her new love Kay by hiding him in the caves and helping him build a makeshift raft that will take him to safety.
Now, the big action set piece that ends the film is curious. I don't know if it's the rough around the edges work of new screenwriters (Lang and his wife Thea von Harbou), or an intelligent subversion of action/adventure convention because it's about Kay saving Lio. They're never less than adversaries, and Kay's motive seems to be more about saving Naela the fate of having to actively participate in Lio's murder, but it's interesting nonetheless. It also coincides with Lio's men arriving on the scene for a big, brash shootout (kind of a less-comedic version of the finale to John Ford's Bucking Broadway) that ends in the caverns of gold that have been booby-trapped and lead to some fun water effects.
Good guys win, get out safely, and, because this is meant to be a serialized story of increasing stakes focused on a singular good guy, things go wrong in the final moments that give Kay the kind of motive to keep on with the fight.
Is this deep stuff? Not at all. Is it built on a fair bit of coincidence and convenience? Very much so. Is it amusing and fun? Yes, it is. It is completely unchallenging, but a fun adventure story that works well enough in the realm of spectacle while it's on. I wouldn't go so far as to call it good, but as a very early attempt from a director in the nascent German film industry, it does its job.
