After experiencing two adventures of the "ultimate" Fantastic Four*--one where they met and battled the Sub-Mariner, and the other where they were instrumental in opening the comics door to the Marvel Zombies--it seems appropriate to backtrack a bit and take a brief look at the circumstances in which this alternate universe team came to be born. Created by Brian Bendis and Mark Millar, the Fantastic Four of (coincidentally?) 2004 had very different histories than their 1961 counterparts, and, by extension, a very different origin.
*There's also the account of the team's own Fantasti-Car--which doesn't look like a "flying bathtub," but was mocked just the same.
It's clear from reading the book's first several issues that a lot of thought was given to not just how these four characters would gain their powers, but how they would come together in the first place. The original Stan Lee story read rather rushed, as far as introducing the four principals, giving us their backstory, and presto, making them heroes in time for issue #2; Lee would then use succeeding issues to flesh out their personalities and begin to cement the bond between them. By contrast, we get to know the characters in the updated story over the course of two issues before the "accident" which created them ever takes place--a scientific experiment that has Victor Van Damme to blame for its failure. (And while "Doctor Damme" has a nice ring to it, rest assured that the good doctor eventually retains the nomenclature that made him a household name for comics readers everywhere.)
To break it down for you, the ultimate FF chronology roughly goes something like this:
We first meet Reed, who's remarkably brilliant even at a young age, as he's being harassed at school by bullies who are sent packing by Reed's friend, the older Ben Grimm, a student nobody messes with and who has become Reed's friend and looks out for him. And when Ben comes over to get some help with his trig homework, Reed confidentially lets him in on his latest brainstorm: a teleportation device.
It would be a few years before Reed actually builds a "working" device to the point where he's ready to present it--at his middle school science fair, that is. To the astonishment of everyone, the demonstration is successful--and it catches the attention of a "scout" who attends such events in order to spot potential candidates for a program that will further their education in an environment which encourages their natural intelligence and creative drive.
And so Reed is invited to live and work at the Baxter Building, a military-sponsored think tank headed by scientist Franklin Storm, where of course Reed meets (biotechnologist) Susan Storm and her brother, Johnny. Reed finds that the staff is very excited to meet him, since they've also stumbled onto the same dimensional-transport discovery that Reed has made but haven't been able to make any further progress.
With Reed aboard, in an environment in which he thrives, in a few years' time he's ready to test the prototype of the device that he first theorized about with his friend Ben when they were kids. Also part of the project is Victor, who Reed met when he arrived at the Baxter. In a turnabout of the history we know, it was Victor who was discovered in Reed's room, looking over Reed's figures for the device and pointing out a few errors--and it was Reed who blew his stack and kicked Victor out in anger. Yet looking over Victor's notes, Reed discovered that Victor had been correct, and later smoothed things over with him and invited him to join in on the project. Now, as the time approaches for the device's first test, Victor is adamant about making last-minute changes to the settings.
And speaking of Ben, he arrives just in time to reunite with his old friend and wish him well.
The test of the device involves sending an apple from Nevada to Guantanamo, a distance of over 2,700 miles. As you might guess, the results are unexpected and dramatic. The apple itself remains stationary; but the effect of the teleporter transports Ben, Sue, Reed, and Johnny while altering their physical bodies at the genetic level (which I probably don't need to go into detail on for you). Johnny ends up in France; Ben in Mexico; Sue in Subterranea, where the Mole Man greets her; and Reed just a short distance from the device. Also affected is Van Damme, who is transported to Copenhagen and now resembles the "Doctor Doom" we're familiar with--only his body is metal, and he has clawed hands and goat-hooved legs.
Reed later discovers that it was Victor who reprogrammed the teleporter; yet Victor believes that the accident occurred because Reed's programming was so bad that even Victor couldn't fix it. (Sanity, it appears, eludes this version of Doom as well as his counterpart.)
The UFF title would run for sixty issues over a period of five years before it concluded, with the book caught up in the events of the Ultimatum series that closed out the Ultimate line of books.