Excalibur are trying to protect Zanzibar from being taken over by the Weaponeers. Lots of fighting. But none of that matters.
The reals story is that, while that is going on, Xavier is trying to pull Scarlet Witch out of the coma she landed in after “killing” The Avengers in the Disassembled event. It turns out that Xavier’s own mental condition needs healing as well, in order to make him strong enough to pull Wanda out of her mystically induced coma, and so Doctor Strange basically goes through some psychoanalysis with Xavier that enables a recounting of the histories and childhoods of Professor X, Magneto, Wanda, and her brother Quicksilver. Strange takes Xavier, via magic, through various stages in the histories of the characters.
A few new details are added, e.g., Charles and Logan actually served together in World War II, and Mister Sinister worked on the human experiments run by the Nazis. Wholly unnecessary, but, hey, it’s building the canon.
But in the end, we really don’t learn very much. These were enjoyable enough issues to read, but they are wholly unnecessary to understanding the event that comes next.
These are the final issues of the relaunched Excalibur. This series never really got going, so it’s not sad to see it end, but it had quite a few interesting ideas and plotlines. I guess that’s just unrealized potential that got swallowed by the line-wide House of M Event. I’m sure that all this was mandated by editorial based on Brian Michael Bendis’ original and brilliant idea of having end-to-end linewide events that actually reference each other (the first time in either Marvel or DC history, I believe), but the execution is very much in the style of Chris Claremont.