Issue number 12 of EXCALIBUR begins a storyline called "The Cross-Time Caper" -- labelled on the cover as part 1 of 9. "Cross-Time Caper" ends in issue #24. Even with one inventory issue along the way (#20), that still means this supposed 9-part storyline actually clocks in at twelve parts! Chris Claremont is known for "writing to the moment" and abandoning his established plans when an apparently better idea comes to him. Presumably, that's what happened here to lengthen "Cross-Time".
Unfortunately, the result is a story which long overstays its welcome. Never mind that sending the heroes of a relatively new series off on an extended trains-dimensional romp, away from their supporting cast and home environs, before they've even hit a dozen issues, is probably not the best-conceived idea -- making that story about two times longer than it probably should've been only exacerbates the problem.
