Cult Review
Senior Film Conservator

Look, if you are expecting a fast-paced sci-fi thriller, just skip Der stählerne Strahl right now. But if you have a soft spot for dusty, black-and-white espionage from the 1930s where scientists wear three-piece suits to work on death rays, you might actually find some charm here. 🛠️
It is definetly not for everyone. Most modern viewers will probably find the endless talking scenes incredibly boring.
The plot is basically about this new invention—the "steel ray"—which can stop engines from a distance. It is supposed to be this terrifying military weapon, but the actual machine looks like a glorified radio transmitter with some extra knobs glued on.
I love how seriously everyone treats this metal box. There is a scene where Karl Ludwig Diehl just stares at a blueprint for what feels like three minutes straight, sweating profusely.
He looks like he is trying to solve a very difficult crossword puzzle rather than saving the nation. It is hilarious.
The pacing is... well, it is very uneven. Sometimes the movie feels as claustrophobic as Trapped in a Submarine, where you just want someone to open a window and let some air into the room.
"We must protect the ray at all costs!"
That line gets repeated in various ways about five times. We get it, guys. 🙄
There is this one actor, Alexander Golling, who plays one of the shadier characters. He has this incredibly intense face and he seems to be acting in a completely different, much louder movie than everyone else.
Every time he enters a room, he slams the door. I actually started counting after the third time he did it.
It is not a masterpiece, not even close. But as a weird artifact of 1930s German cinema, it is a fun little watch on a rainy Sunday afternoon when you have nothing else to do.

IMDb 6.3
1929