The first Spiders movie was a relatively small and focused adventure. The second is bigger and far less focused, moving from one to location to the next in an amorphous mystery that doesn't so much escalate with increasing stakes but just kind of lurches from one thing to the next. There had been planned two more episodes in the Spiders saga, but they got canceled. I can't find reasoning for it, but I would imagine it to be simply financial. They didn't make the kind of money needed to recoup investments, and Fritz Lang went off to make smaller dramas for a couple of years. I suppose the German appetite for adventure stories wasn't that deep at the time.
Kay Hoog (Carl de Vogt) is out for vengeance against the criminal enterprise The Spiders and, in particular, one of their members Lio Sha (Ressel Orla) after Sha killed Hay's love at the end of the previous episode. The Spiders are on the move, though. They are determined to find a special diamond, formed in a way that resembles Buddha that, if used correctly, will give them control of all of Asia. There's an unexplored set of ideas about imperialism here with the Spiders trying to overturn one imperialistic regime to replace their own while Kay does not seem to concern himself too much with the question at all. It's an interesting beginning of subtext that the movie is completely unconcerned with mining.
Anyway, Kay has to pursue the Spiders into an underground Chinatown in San Francisco (kind of a proto-Big Trouble in Little China) where he gets clues and stows aboard a Spider ship (the eponymous diamond ship) that is headed towards South America. They receive a telegraph from Fourfinger John (Edgar Pauly) that John Terry (Rudolf Lettinger) has the diamond in his possession due to his relationship with the man who discovered it hundreds of years before. Kay finds this information out by sneaking out of a shipping box at night, complete with silly looking ninja-like outfit, and reads the telegraph message. In England, the Spiders kidnap Terry's daughter Ellen (Thea Zander) as leverage to get Terry to reveal to them the location of the diamond. Kay escapes the ship, connects with Terry, and together they discover that it is probably hidden in a secret treasure cave on the Falkland Islands. So...the chase moves again to the Falklands for the final confrontation.
I have nothing against globe trotting adventures, but the structure has to be there to support the move from one place to the next. It isn't helped by the fact that most of what we see are simply sets that could be pretty much anywhere. We're not even getting an exciting moment on Big Ben or something. It's just a room in England. The mystery itself feels really amorphous, like the people involved are bumbling from one thing to the next, spinning their wheels and getting no closer for most of the film. The trip down to Chinatown is a great example. It gets Kay on the boat, but we get no advancement in the mystery. That advancement, the notice that Terry may know where the treasure is, comes while they're going towards South America, is surprisingly thin. It doesn't feel like an advancement, and Terry not knowing is unsatisfying as well. The advancements we do get are so small that it feels more like the movie is just elongating the action to fill out the runtime.
That being said, it's not a complete slog. At only 104 minutes, all this action does keep the thing moving. The brisk pace doesn't let the film get too bogged down in the meaningless detail of the mystery. The few bits of action are clearly filmed, and the production design is nice, though not as fun or impressive as the Incan city set in the first film or the Japanese city in Harakiri.
This isn't exactly the worst film I've ever seen, but it is a surprisingly ineffective mystery and thriller. It feels like a young filmmaker getting ambitious and working too quickly to iron out important narrative details.
