Three crooks try to grab a load of raw diamonds from a big ship, but things go wrong for them.

Keith Roberts, a worried man, goes to see psychiatrist Dr. William Jackson for help. Keith tells a strange story about a blast in Montana that he thinks came from a spaceship from Mars. After many odd things happen to him, Keith ends up locked away in a mental hospital because no one believes him anymore. Then Keith discovers something shocking - his doctor is actually a Martian.