The issue opens on a young boy. he wanders through his town noticing that something is not quite right. The sun does not shine. Nor does it seem that that even the noises have changed. We then cut to Superman who is being summoned by the JLA. It seems that major parts of the world are just falling asleep.
That is when Morpheous appears to the JLA. The boy we met in the first few pages is in the dreaming. An alien presence has taken hold of a large city, and it is his faith in the League that the Sandman wants to exploit in order to free them. Wonder Woman, Green Lantern and Superman enter the dreaming. Leaving the rest to discover what they can on the outside.
As they do this the Justice League in the dreaming discover they have no powers, and are against a million mind controlled people, yet no one knows exactly what they are against, until Martian Manhunter takes to the skies and sees just how large the problem really is.