With Reed Richards and Ben Grimm still desiring to change back to normal, Richards develops a controversial plan to enter in the N-Zone, believing that the only way to have a chance at reversing the effects of the sabotaged experiment now lies in knowing as much about the N-Zone as possible. After a campaign to entice the government to aid his mission by giving him the supplies he needs to build a suitable craft, the yet-to-be-named Fantastic Four enter the N-Zone.
At first, the N-Zone looks like an empty dying universe, but soon they come across a space station. Reed Richards, desperately wanting to have found a new sentient species who can share information with him (and Earth), quickly agrees to meet the leader of this alien race. With omens of danger surrounding them, Richards is unfazed and seems to quickly trust Nihil (aka Annihulus), the leader, who confirms Richards suspicious that this is a old dying universe located below the relatively young universe in which the Fantastic Four come from. However, they're conversation is cut short when Johnny Storm suddenly falls unconscious, his body now gray and covered in what looks like scales. Rushing back to their shuttle (named Awesome by Reed Richards) Susan Storm examines her brother to discover that the effects of his new powers are killing him - killing him fast. She demands they leave the N-Zone immediately for fear that any delay will result in her brothers death. Reed understands and agrees but is clearly torn, feeling his life's dream is now slipping away.
While Sue watches Johnny, Reed Richards and Ben Grimm return to the alien space station to explain the situation to Nihil and quickly discuss setting up a way to communicate between their universes so that they can share information and help each other. However, this time, Nihil reveals his true nature and tries to kill Richards and Grimm so that he can hijack their craft and leave his dying universe. His plans ultimately fail, as Ben Grimm has abilities not even Susan Storm or Reed Richards had discovered yet and is able to fight off Nihil's army and help Reed make it back to their craft, the Awesome.
At full speed, they rush back to their portal but Nihil has more fight in him yet. Soon, giant winged creatures/spacecrafts are chasing them and firing upon them. Nihil is determined to make it to their universe and his backup plan is a simple one - follow the Awesome to and through the portal and invade the Fantastic Four's universe. Nihil barely accomplishes the first part of his plan, to follow the Awesome through the portal, but due to the speeds of both the Awesome and Nihil's craft, the miles of desert between the portal and Las Vegas are insufficient for the vessels to stop before reaching Vegas and both crash land in the middle of Vegas - in front of many many people.
With Johnny Storm still comatose, the remaining three Fantastic Four quickly try to neutralize the alien threat but instead find themselves neutralized. But, luckily, when things seem grim, Johnny Storm tiredly walks out of the Awesome wondering what happened and where he is. Upon seeing the situation, excitement overcomes his sleepiness and he turns the battle around and the Fantastic Four defeat Nihil and his army.
Arriving after the battle is over, General Ross is furious but his anger dissipates as soon as Reed Richards gives him one of the alien weapons - a "hand-held death ray" - that Richards claims will be easy to reverse engineer. And now that so many people have seen the Fantastic Four and what they are capable of, the government can no longer hide them and deny their existence and perhaps now they can become the super heroes they are destined to be.
Reprints Ultimate Fantastic Four #13-18.