Lester del Ray: Dead Ringer
There was nothing, especially on Earth, which could set him free—the truth least of all!

There was nothing, especially on Earth, which could set him free—the truth least of all! Dane knew a terrible and wonderful secret but no one would believe him. He needed to tell the world of this but he has smashed his head against that wall too many times to think it possible any more. They thought him insane at best and evil at worst. Suicide would end his troubles. But was suicide even possible? No, it was not. Not for a Dead Ringer.