The thirties horror films that are best remembered are always the likes of Dracula and Frankenstein; and there's a very good reason for that, but there were a number of smaller but nevertheless excellent productions, and The Invisible Ray is certainly one of them. The plot is not particularly original and similar plots have been seen many times before (even way back in 1936) but the way that everything is put together is certainly very imaginative and director Lambert Hillyer has created a very nifty little original horror film. The plot focuses on the good hearted Dr Janos Rukh; a man who has discovered a way to recreate the history of the Earth. His discovery leads him to believe that there may be an unknown radioactive element somewhere in Africa and so he sets off along with a team of esteemed colleagues to find it. However, tragedy strikes while on the expedition and the good doctor ends up becoming exposed to the element; which makes him glow in the dark, and also sends him mad...<br /><br />The biggest draw of the film is undoubtedly the fact that it stars the two biggest horror stars of its day - Boris Karloff and Bela Lugosi, and both give excellent performances. Karloff really shows what a good actor he is and his character has plenty of meat for Karloff to impress with. Bela Lugosi has a role which is extremely different from what we're used to seeing him in, and it's a great performance from him also; it's nice to see a bit of versatility from Lugosi. The film does get off to a rather slow start; but things soon start to pick up. The second half of the film is the best and that's really when the film gets exciting and Karloff gets a chance to shine (literally). The film does not put its focus on big special effects and largely relies on the actions of the central character to keep things interesting; and it does work very well. The film remains interesting throughout and boils down to a very decent climax that wraps everything up nicely. Overall, The Invisible Ray may not be one of the very best horror films of the thirties; but it's a very good one and comes recommended.