Mr. Fantastic was a part of an elite group of heroes called the Illuminati that met periodically to exchange information about the hero community. The other members of this group include Iron Man, Black Bolt, Dr. Strange, and Namor. The group dissolved after they decided to exile the Hulk into space due to his constant threat.
At the insistence of Iron Man, they met one final time. He presented them with an early draft of the impending Superhuman Registration Act. This bill will require all those with powers - mutants included - to register with the Federal government, be trained in the use of their powers, and be held accountable for their actions. Failure to comply with this bill will be considered a Federal offense.
Unable to agree among themselves what should be done, the group walked away waiting for the time when the bill became law.
Six months ago: an unidentified object a few feet in length entered the Earth's atmosphere and crashed into an empty field in Oklahoma. Independent astronomers cannot identify it nor can any national space agency.
Now: Reed returns to the Baxter Building at 4 AM after the final meeting of the Illuminati. He grabs a sandwich and turns on CNN. Despite Reed's best intentions to avoid waking her, he soon finds Sue standing next to him. She asks him how the meeting went. He admits that there are some bad times coming and that they could not agree on a course of action. He hopes that in the long run their differences will be worked out.
At this point CNN replays footage of Tony Stark and Peter Parker leaving the meeting with the Senate Committee on Superhuman Affairs. Tony gives an indirect answer on the possibility of a Superhuman Registration Act and quickly leaves.
Sue is concerned about this development but quickly states her belief that this is simply election year tactics. Reed tries to tell her otherwise but they are interrupted by a distress call on a private frequency. The caller is general William Ray, who has acquired the frequency from S.H.I.E.L.D. since they will not be able to respond in time. Minutes later Reed awakens the rest of the team and leaves for a research facility in Oklahoma. This facility was build around the space object that crash landed six months ago.
It seems that the military forces stationed at this facility are under attack by Doombots. The new Latverian government want the object. News of this object's arrival has been kept secret but somehow they're aware of it.
While Thing, Human Torch, and Invisible Woman turn the tide against the Doombots, Reed is brought to General Ray. Reed informs the general that the robots are doing nothing more than forming a perimeter around the base and asks for additional information. The general admits that they'll be unable to get any as their battlefield imaging systems are off-line.
At this point Reed sees the incoming missile and orders everyone to get as far away as possible. The missile levels the facility and leaves nothing but the crater containing the object.
At this point Dr. Doom emerges from the smoke to announce his return. He explains that his moles in the U.S. government were only recently able to provide the exact location of the artifact, which rightfully belongs to him. As they look into the crater, the "object" turns out to be Mjolnir, the hammer of Thor.
Picking up after the final meeting of the Illuminati, we find Reed Richards returning home to an impending change in the status quo in the form of the SHRA. At this point the heroes are unaware of what lies in store for them and remain somewhat optimistic about the future.
This issue acknowledges the topics covered in New Avengers: Illuminati, shows Reed's reaction to it and quickly transitions into a new storyline involving the attack of the Doombots and the surprise return of both Dr. Doom and Mjolnir. Thor died in Thor (Vol. 2) #85 and Doom was literally sent to Hell in Fantastic Four #500. Bringing both of them back in one issue is risky but so far so good.
It's obvious that the creative team is trying to delay most of the Civil War talk for a few months and have one last two-part story before going into crossover mode. This is done in a believable way, so I'm not complaining.
3.5 webs. Two major events incorporated into one issue and it's done in an enjoyable way.
The Illuminati exiled the Hulk into space in Incredible Hulk Vol. 2 #91
As stated above, in Fantastic Four #500, Reed had literally trapped Doom in Hell. After three years, it only makes sense that Doom would return, but the big question is how? These questions are answered in the next issue (not reviewed here, sorry).
From this point, go straight to Civil War #1 to continue with the Civil War crossover.