Doctor Janos Rukh (Boris Karloff) has invented a machine that enables
him to look into earth's past, where he & a selected group of
scientists see a meteor crash into Africa some 13 million years ago. So
he, doctor Benet (Bela Lugosi), Sir Francis Stevens (Walter Kingsford),
his wife (Beulah Bondi), her explorer-nephew Ronald (Frank Lawton), &
Rukh's own wife Diana (Frances Drake) all embark on a mission to Africa to
collet some meteor material ...
In Africa, while tender romance between his wife & Ronald starts to
blossom, Rukh leaves the rest of the expedition for days on end, &
soon finds the meteor, is able to harness the power of its key element
Radium X, & soon has a raygun that melts stone (!) ... but of
course, his success comes with a price, at night he glows & his touch
proves to be lethal. He begs Benet to cure him, but Benet can only give
him injections to supress the effect of Radium X, without the injections
Rukh would probably go up in flames & then die ...
At the same time though, Benet has noticed that Rukh is borderline mad,
since he wants to use the Radium X for his own purposes, he steals some of the element, to use it in medicine ... to terrific results, Radium
X can make the blind seeing again & so on.
When Rukh hears about what he thinks is Benet's treachery, he is at
first furious, but then pretends to be impressed after all &
congratulates Benet to his progress ... & that same night, he fakes
his own death.
Later, Ronnie & Diana marry (everyone has seen it coming) &
couldn't be happier, while Rukh plans to kill all the participants of the
expedition, starting with Sir Stevens & his wife ... but Benet takes a
ultra violet photograph of the iris of dead Stevens & finds out the
last thing he has seen was Rukh. So he, Ronald & the authorities
decide to set a trap for Rukh, inviting a panel of notable scientists to a
midnight demonstration of the effects of Radium X.
Somehow though, the trap hasn't been all that thought through, because
Rukh has no problems catching Benet alone & murdering him using his
touch of death. Then he makes a visit to Diana in her (unguarded) room,
but just can't bring himself to kill her because of the feelings he still
has for her. Instead he wants to go after Ronald, when Rukh's mother
(Violet Kemble Cooper) interferes, scolds her son & breaks his
hypodermics with the serum he needs to survive.
The effects are immediate: Rukh's body starts emerging smoke, then he
goes mad & throws himself out of a window. & his body burns to
cinder before he even touches the ground ...
Of course the film is silly, the narration doesn't make any sense &
credibility is strained beyond the limits. But Invisible Ray is
also highly likeable, a pulpy mix of horror, science fiction &
adventure featuring straightforward storytelling, a fine duel Karloff
versus Lugosi, & a genuine love for its subject.