Sandman 3 (June/July 1975) once again has a Kirby cover, but a story by Fleisher, Chan and Royer. It is also the only issue of the run in which Jed does not appear.
The story begins in Europe, one assumes, as angry villagers storm the castle of an evil count. The men has created gorillas with electronic brains (not unlike that of General Electric, though there seems no connection). The count drinks poison before the villagers can get to him. His gorillas disguise themselves as humans to retrieve his corpse, which they then bring to another mad scientist.
That guy removes the count's brain and puts it in a big beaker, providing it with a mouthpiece and speakers. Somehow it can even hear. But does the count's brain appreciate this? Well, yes, but he still kills the guy. The count then commands his gorillas to help him steal the formula of a scientist who is working on how brains can acquire greater power though absorption.
The mind of the count enters the dreams of a little girl, Susie, the daughter of the scientist, commanding her to help the gorillas steal her father's notes. This registers as a nightmare on the Sandman's monitors, and he comes to help Susie.
The gorillas still manage to steal the notes and bring them to the count's brain. Some cops get on the case and kill the gorillas, but by the the brain has read the notes. Somehow. He kills the cops and is able to leave the beaker, floating through the sky as he gets larger and more powerful. There is a fairly lame bit in which the police arrest Sandman and toss him in prison. Brute and Glob once again come to rescue him.
Then there is a really quick resolution. Sandman faces off against the brain, which creates a nightmare image for Sandman to fight. Sandman uses his sonic whistle, destroying both the monster and the brain.