Neal Adams goes solo on Spectre 4 (May/June 1968), and delivers the best issue so far.
Once again some energy from outer space comes to Earth, and this time it smacks into a young boy in a small town. The boy goes missing, which brings Jim Corrigan onto the case.
When Jim cannot find the boy he turns to the Spectre. The Spectre is able to locate him, but finds the child possessed by an evil spirit, bonded so strongly to the boy that the Spectre is unable to remove it without killing the kid.
The Spectre decides to hunt out the source of the evil, and follows its trail through space, winding up on world after world where evil has taken complete control of the planets. Although the Spectre can see the results of this, he cannot figure out how the evil actually manages to take over entire worlds.
Returning the Earth, the Spectre tries to stop the destruction the boy is causing, but can find no way to do this permanently, so long as the evil spirit is in control.
It comes down to a choice between saving the world or saving the child. Removing the evil spirit will kill the boy, and there is no way around that.
The Spectre comes to the (very un-Spectre-like) decision that he cannot kill the child. This causes the evil spirit to flee the boy, and take off. The Spectre cannot figure out how he achieved this, though Jim Corrigan can. He theorizes that the evil spirit conquered worlds by corrupting the greatest force for good. In this case, the Spectre was his real target. Had the Spectre killed the boy, that would have caused the evil to take him over, and spread throughout the world.