Synopsis
We start with a prologue where an unidentified voice is talking to his
daughter Katie. He tells her that he and her mother are going on a
deadly-dangerous mission to put things right. (There was a similar
opening to #14.)
Henry Pym, Iron Man and Vision are working with Dr Doom to expand Doom's forcefield to encompass the whole Earth, as Iron Fist and the Doc Ock Spider-Man try to calm the local population. The scheme needs Hulk to keep a pair of electromagnetic 'anchors' in position. Meanwhile Dr Strange leads a troop of superbeings (including Captain Britain, Hyperion, Iron Patriot and Machine Man) to try to delay the approach of Exitar the Celestial Executioner, here to destroy Earth for the death of some Celestials.
Meanwhile Thor battles the Apocalypse Twin Eimin in space for the axe Jarnbjorn which has the power to kill Celestials. He has already slain her brother Uriel for it last issue. Eimin claims she foresaw Uriel's
death, but her hatred of Kang and humans drove her to continue with
their plan. They crash into the space ark which is taking all mutants
to safety.
On that ark Wasp is trying to shut down the Tachyon Dam which is
stopping Immortus from sending his forces through time to help them.
But Grim Reaper is preventing her. The Twins brought him back from death, and he wants to return there. If Wasp kills him then she can reach the Dam. But he taunts her that thus would make her no better than Wolverine, whose involvement in the death of Archangel split the Unity Team during this storyline.
Dr Doom's forcefield is keeping Exitar out as Hulk strains to keep 2
electrodes in place. Thor buries Eimin under rubble and takes
Jarnbjorn. He hopes to use it to persuade Exitar to spare Earth
because it was the Twins who used it to kill Celestials. But if not
then he is prepared to kill Exitar himself. Doom's machinery suddenly
explodes, and the forcefield starts to fail.
Grim Reaper tells Wasp what is happening, and that she's now the only
hope - she *must* kill him. But then Captain America bursts onto the
scene to resolve her dilemma. He'll hold Reaper off while Jan destroys
the Dam. But her Stingers are depleted after fighting Sentry in #15.
And Reaper kills Cap before she can succeed.
Thor's rhetoric has no effect on Exitar. And then Eimin returns to the
fight. She regains Jarnbjorn which wounds even the Thunder God. And Exitar destroys the Earth, as the Watcher watches on. And in the ark Eimin gloats that Kang now has no future planet to rule.
As the ark leaves, Thor uses Mjolnir to create a spacewarp to take him
to Asgard where Odin awaits him. Thor blames himself for having made Jarnbjorn capable of killing Celestials (#6). Odin lays the blame more on squabbling humanity. If the Unity Team hadn't split they would have been able to save the day. (He makes a bigger point that mankind would only achieve their place among the Galactic civilisations if they could put aside their petty differences.)