UPDATE: Added alternate Mediafire links for comic book lovers outside the U.S. and Deutschland, more specifically anyone who can't access Rapidshare. It's interesting how Superman played pivotal roles in seminal Batman works such as The Dark Knight Returns and Hush, but the opposite did not happen here. But that's a testament to the threat faced in this story and the very fast pacing that results from it. There's just no time for much thought or talk, given the short timespan of the encounter--a violent and heated brawl.
The source material for this trade paperback spanned the four different Superman publications at the time, as well as Justice League America. An ominous countdown sequence is started in Part 4: Every page in this chapter is composed of only four panels; the subsequent chapter (Part 5) only has three panels per page; Part 6 only has two panels per page; and Part 7 only one...
Part 1 - Doomsday! (Superman: The Man of Steel #18): Rapidshare / MediafirePart 2 - Down for the Count (Justice League America #69): Rapidshare / MediafirePart 3 - Countdown to Doomsday! (Superman Vol. 2 #74): Rapidshare / MediafirePart 4 - Under Fire (The Adventures of Superman #497): Rapidshare / MediafirePart 5 - ...Doomsday is Near! (Action Comics #684): Rapidshare / MediafirePart 6 - Doomsday is Here! (Superman: The Man of Steel #19): Rapidshare / MediafirePart 7 - Doomsday! (Superman Vol. 2 #75): Rapidshare / Mediafire