The Negative Zone is a largely uninhabited parallel universe within the Marvel Multiverse. Unlike most universes (which came into existence based on deviations from the 616 timeline), the Negative Zone is unique and separate in its existence.
The Negative Zone has a few bizarre qualities. It is completely composed of antimatter so entering the Zone requires reversing the polarity of all atoms arriving from a positively-charged universe. The entire universe is filled with a pressurized oxygen-rich atmosphere, making it possible to live in space. However there is a mysterious lack of gravitational pull; few planets are able to acquire sufficient mass to sustain life.
Currently the Negative Zone is collapsing into a singularity, the process resembling the "Big Crunch" theorized to be the end of our universe. Most of the inhabitants of the Zone believed that the singularity leads to death. In reality it is the Crossroads to Infinity, a dimensional gateway that conceivably leads to all other universes.
During the Civil War, it is used as a jail for captured mutants who refuse the Super-Human Registration Act. The area is monitored by robots, and the specific jail is officially known as the Negative Zone Prison Alpha, yet it is more commonly known as 42. Shortly before Secret Invasion, an amount of exotic radiation was found within the Negative Zone and held with the Quantum Flask.
After gathering several reports from various spies Blastaar, who was recently appointed supreme ruler of The Negative Zone by Emperor Ronan of the Kree, and a massive army of Negative Zone inhabitants have stormed 42 and are preparing for a full-scale invasion of Earth. Peter Quill a.k.a. Star-Lord, who was recently exiled to The Negative Zone by Ronan, is being forced to aid Blastaar in the attack on 42. Thanks to the timely assistance of The Guardians of The Galaxy along with the unregistered super-hero Jack Flag; StarLord was able to escape and warned Reed Richards, Gauntlet and Baron Von Blitzschalg about Blastaar's armies.
The gates to 42 were shut down and The Negative Zone was sealed off from Earth-616. At the same time Blastaar turned 42 into his own personal fortress where he met with the last two surviving members of The Fraternity of Raptors - Talon and Razor - who forged an alliance with Blastaar and as a sign of good faith gave him The Cosmic Control Rod. One major problem has arisen however, due to lack of information transference, Norman Osborn knows nothing about Blastaar having taken control of 42 and following the capture of Hardball has reopened the gates to 42. With the gates back online Blastaar and his armies are waiting in hiding as the gates reopen, ready to strike and cross over to Earth-616 at a moment's notice.
When Big Brain went offline, the remaining members of the Fantastic Five went to investigate what happened to Mr. Fantastic. As well as Human Torch, Thing, Ms. Fantastic and Franklin Richards, Stinger replaced Big Brain. They found Reed to be protecting his wife Susan, aka Invisible Woman from dying whilst she patched together holes in reality.