There is a good cheat-sheet for "Multiversity" #4 to be found here.
http://heshouldreallyknowbetter.blogspo ... icana.html
The structure of the book itself is part of the overall meta narrative and commentary on the nature of comics, rather than the plot per se, which barely even ties into the other Multiversity issues.
Every issue of "Multiversity" is meant to stand alone as an example of the world it is set on. Last issue's Earth 16 was about shallow egocentricism. This one is about stylistic narrative. It took me about 30 minutes to get through this book, and I was still digesting it an hour later.
I’ve read reviews of the issue from around the web where people are just gushing praise for how brilliant the book is, and while I think a lot of reviewers are overstating the case, I will admit that it clearly took a lot of skill and meticulous planning to lay this book out, so credit where credit is due.
The technical skill needed to plan, never mind execute, a single issue like this is why is warrants every big of praise it has gotten.
This, more than any issue of "Multiversity" (arguably anything Morrison has ever done) was going to be be scrutinized. "Morrison riffs on Moore" implies and obligates a ridiculous standard of scrutiny and analysis...and Morrison not only delivers, but tells people they are wrong to appreciate his work. But, he says it in a recursive way, so that the only way to get what he is saying is to have already done the thing he told us not to do and....
I’m willing to bet that he’ll turn up later in the series, possibly even as a pivotal character. He doesn’t seem to have been corrupted in the same way that Alexis Luthor or the SOS characters were, interestingly.
The general assumption is that "Pax Americana" precedes "Final Crisis", and that Allen Adam went to Limbo ("Superman: Beyond" #1 and #2) after disappearing.
The plot is partially a series of paradoxes, where the time-traveling Captain Atom inspires Harley’s actions, and then Harley in turn inspires Captain Atom to go back in time and speak with him. And we get the infinity symbol turning up throughout the story, with the final appearance as the dead Yellowjacket’s domino mask, while a character comments at one point about getting the same stories over and over only a bit different each time.
This one tied in most directly to "Final Crisis". The 8/infinity rune theme and Adam's breaking the fourth wall are not only references to viral information, they also call back to the 80s, when Morrison got his start.
The algorithm is probably a reference to the Anti-Life Equation.
And, the page layouts force the reader to physically react and interact with the book, representing both the viral nature of information (impacting the real world) and the reader's will being subverted.
Grade: A This book was worth the wait.