By Jim BeardASTONISHING X-MEN has, in its relatively short existence, proven to be nothing short of astonishing. With a dream team of writer Joss Whedon (TV's "Buffy the Vampire Slayer" and "Firefly") and superstar artist John Cassaday, the newest of the X-titles rose swiftly to the pinnacle of creativity and captured the hearts and imaginations of comic fans everywhere. Whedon and Cassaday brewed up a magical elixir of unforgettable characters, richly satisfying dialogue and heart-stopping visuals that pleased the most die-hard of X-fans and brought readers young and old to the edge of their seats. In short, ASTONISHING X-MEN has been built for speed and built to please...and please it has. Now after 18 issues, the book is prepped and ready for its final storyline, with Whedon and Cassaday primed for the ultimate in X-adventure and the deadly culmination of their tenure. "Unstoppable" is a juggernaut of a story that's the epitome of "must-read". As "Unstoppable" approaches, Marvel is proud to present the Astonishing X-Men Saga, a vivid recounting of the first 12 issues of ASTONISHING X-MEN, in Digital Comic form, here on Marvel.com. "Gifted", the first story arc, opens with a bang, and then proceeds to shake the timbers of the venerable X-mansion. Founding member Cyclops gathers together a leaner, meaner team of mutants, set on a new, proactive course of heroism and service to the Earth. Wolverine, Beast, Kitty Pryde, and Emma Frost join their leader in a headlong plunge into direct conflict with the mysterious new villain--Ord of the Breakworld, while the world is told of a miraculous new "cure" for mutations. The X-Men's struggle against both problems is intense and breathtaking and while the team is stymied at each turn, they're also rocked back on their heels by the return to life of their much-beloved teammate Peter Rasputin, a.k.a. Colossus. The X-Men barely have time to breathe before their own training ground, the wondrous Danger Room, gains a hideous and independent semblance of life, in "Dangerous", the second story arc. "Danger" wants the mutants dead, and holds the entire population of Xavier's School for Gifted Youngsters hostage with truly wicked intentions. Fortunately the school's founder, Prof. X himself, returns triumphantly to help the X-Men route the cybernetic demon, driving it out and bringing peace once again to the mutants' world. Then things get really interesting. The Hellfire Club, the X-Men's old and decidedly dangerous foes, blast onto the scene, led by the devil incarnate herself, Cassandra Nova. "Torn" the penultimate Whedon-Cassaday story arc, is a sordid tale of evil, mystery and betrayal. The X-Men's minds and souls are peeled back layer by layer and their deepest desires and innermost fears are exposed. To add insult to injury, Ord of the Breakworld and Danger draw together in an unholy alliance, attacking while the X-Men are at their lowest, their psyches raw from the combined torture of Cassandra Nova and the traitorous Emma Frost. The lines between reality and fantasy blur and the mutants claw their way up from their pain and valiantly bulwark against the invaders, both familiar and strange. A mysterious box, deep in the X-Men's mansion, holds the key to Cassandra Nova's breathless sortie against her adversaries. Ord also returns, renewed in his quest to stop the one X-Man who his people have foreseen will one day bring them complete and utter destruction. Danger's urge to revenge herself on her supposed-tormentors is undiminished, and Emma Frost, manipulator and manipulated, must look deep into her own soul and ultimately decide where her true loyalties lie. All sides meet and the confrontation that ensues is brief yet violent... Now..."Unstoppable". The X-Men have never been challenged like they will be in "Unstoppable". Writer Joss Whedon and artist John Cassaday deliver the work of their careers in a story that delivers the X-Men out of the hands of their enemies and into the crosshairs of an entire world that wants nothing more than the mutant team's complete obliteration. Breakworld fights for survival, and that survival just may come at the cost of the lives of Earth's champions, the X-Men. After this, nothing will or can be the same. The characters, the action, the danger and the peril: all "Unstoppable". It all begins December 27 in ASTONISHING X-MEN #19.