Generally, with DCU-wide crossovers, I go for all Superman and Batman tie-ins, and the crossover volume usually stays with my Superman collection.
Showcase ’94 #8-9 (lead stories)
Superman: Man of Steel #37
Zero Hour #4
Zero Hour #3
Zero Hour #2
Adventures of Superman #516
Action Comics #703
Guy Gardner: Warrior #24
Zero Hour #1
Zero Hour #0
Showcase ’94 #10 (last story)
Batman: Shadow of the Bat #31
Detective Comics #678
Determining the placement of some of the tie-ins were tricky for this crossover, as the main action of Zero Hour took place over a 32 hour period, as specified by the captions in the main ZH mini-series. Several tie-ins just dealt with generic time anomalies that did not necessarily have to occur within the 32 hours chronicled in the main Zero Hour series. Also, all of the issues that came out during the final week of the event all ended with everything fading to white and have to be placed prior to Zero Hour #1 (as #1 continues directly into #0).
-Batman #511 and Man of Steel #37 were easy to place, because they share scenes with each other and the early part of Zero Hour #4. By the time Batman #511 ends, there’s only 24 hours left until Zero Hour.
-SOTB and Detective both have generic time anomalies. SOTB #31 makes a reference to the Batgirl they met “a few nights ago” in Batman #511, which obviously cannot fit in during the timeline established for the main event. Detective #678 deals with Batman conducting a calm patrol of Gotham. I have a hard time assuming that Batman would find the time to break away from the chaos of Zero Hour just to patrol Gotham and then study open cases at the Batcave. Therefore, I opted to move both of those issues after the main event, with the assumption that even after the heroes fix the timeline, there are still a few residual aftereffects occurring.
-Superboy #8 has the message from Superman to all heroes that occurs in the middle of Zero Hour #4, and we see replayed at the beginning of Superman #93. An argument could be made for putting the issue on either side of Zero Hour #4.
-I originally placed Adventures of Superman #516 before Zero Hour #2 until I realized that only 11 minutes pass between Superman’s appearances in ZH #3 and ZH #2, and the events around that gap are not conducive to Superman leaving the main action and having a side adventure. There is enough of a gap between ZH #2 and #1 for Superman to have two adventures, especially if he’s getting shunted into alternate timelines where time could move at a different pace.
-Robin #10 has a fade-to-white ending. There is enough of a narrative gap between Zero Hour #2 and #1 (roughly six hours based on the captions) for Robin, who appears in both issues alongside Batman, to get back to Gotham to have his adventure, which includes a young Dick Grayson. Robin going back home for a brief spell can be explained away simply as Batman sending Robin back to keep an eye on Gotham, but then Gotham starts disappearing, thus forcing Robin to return to the main action in New York. The order of Robin #10 and Action #703 is interchangeable. I think I opted to break up the Superman action by putting the Robin issue in the middle.
-Guy Gardner: Warrior #24 guest stars Steel, Supergirl, and the time displaced Batgirl, and it leads directly into the opening scene of Zero Hour #1.
-Showcase ’94 #10 is supposed to take place at the same time as the end of ZH #1, but it would ruin the tone and pacing if placed there, so I use it as an epilogue.
-In an earlier version of this map, I included the three Justice League related books (Justice League America #92, JL Task Force #16, and JL International #68) right after Zero Hour #2. The three books form one linear story that ends with a fade to white. I have since dropped that arc from the map, because I just didn’t care that much for it, and it really slows the pacing down.