Page "Negative Zone" Paragraph 13

While searching for a way to travel through sub-space, Reed Richards stumbled upon a gateway to the Negative Zone.

He spent a fair amount of time studying it through probes, and determined that it was largely unpopulated.

So much so, in fact, that he-and others-used the Negative Zone on several occasions to get rid of difficult enemies, such as the Mad Thinker's android, the Super-Adaptoid, and even Galactus.

Reed and the Fantastic Four have since done more detailed explorations of the Zone and no longer use it to dispose of villains.