Federal Communications Commission (FCC) investigators arrive in the San Fernando Valley after what appears to be a flying saucer crash, causing massive interference with tele-radio transmissions. During their investigation, they receive eyewitness reports of what appears to be a man dressed in a bizarre outfit, which appears to be radioactive and thus a public threat.
Their investigation uncovers this man is actually a humanoid creature from outer space, who is invisible without his suit. They start a massive manhunt for the radioactive invisible alien running loose.
The action culminates in Los Angeles where the invisible alien has been tracked. He becomes trapped inside the famous Griffith Observatory. The woman lab assistant discovers that he can be seen using ultraviolet light. The alien attempts to communicate by tapping out a code, but no one can understand the code. Now breathing heavily because his breathing gas reserves are running low, he is trapped high-up on the Griffith telescope's upper platform. Because he can no longer survive without his breathing gas, he falters and then falls to his death. His body briefly becomes visible before completely evaporating
who  attempts to communicate by tapping out a code, but no one can understand the code?
the alien