Superman is in shock on the cover of issue 103 (Feb. 56).
Mr. Mxyztplk is back in a story by Schwartz and Plastino.
The character looks more malevolent than in previous appearances, and his actions in this story are more destructive. He has some “insurance” that prevents him from returning when he says his name backwards.
Lois Lane is the one to suggest the “x” element – that all the places where Mxyztplk does his magic have an x sound at the start of their names. Superman changes an exposition to a fair, and sure enough, Mxyztplk’s “insurance” no longer works.
The cover story, by Boring and Kaye, is fairly obvious and predictable.
Superman is a volunteer at a mind-reading show, and the mentalist apparently succeeds in reading his mind, and learning Superman’s identity. This is broadcast in the press. The mentalist then offers his services to criminals. He does not reveal Superman’s identity, instead he reads Superman’s mind during pursuits, and allows the bad guys to get away.
Eventually, the mentalist gets a big group of criminals together, to reveal Superman’s identity – but really just to round them all up. It was all a big hoax, with a policeman pretending to be a mind reader.