Synopsis
Kiri Oshiro and Lila Rhodes have come in their giant armoured Moving Fortresses for vengeeance for the murders of Lila's uncle Jim Rhodes (Marshall of Technopolis and the local represenative of Dr Doom's Thor Corps) and Kiri's parents (and also Spyder-Man and his uncle). They face Baron Tony Stark and his brother Arno and the armoured troops who used to work for the now-dead Wilson Fisk. Fisk's men are nearly all downed when Arno brings in reinforcements - an army of Machine Men.
While the battle rages we concentrate on a war of words between Kiri and Tony. She wants to know why he did all this. We flashback to #3 where business rivals Tony and Arno met for a chat, and we learn what Tony told him then to form an alliance. Tony warned Arno off making any more attacks on Kiri (like #2's Stingray) because it's important to keep her and Lila alive. Not because of the giant mecha they are building but because of some aspect of it that threatens the Stark family secret.
Tony now explains further to Kiri. His father Howard Stark created the disease that forces the inhabitants of Technopolis to live in armour - armour mainly suppled by his firm. To help keep this secret Howard fitted his suits with a neural inhibitor which prevented the wearers from trying to discover the source of the plague.
Later Tony used Kingpin Fisk's criminal organisation to keep an eye on things. Including getting Fisk to pretend to work with Arno. He also allowed Arno to 'steal' some of his secrets so that the the armours his company produced had the neural inhibitor too.
Kiri's parents developed a firewall that accidentally bypassed the inhibitor. They began to ask questions, and took their suspicions to reporter Ben Urich who uncovered the truth. They all had to be disposed off. Kiri's boyfriend Peter Urich, Spyder-Man, had an armour infected by a Spyder Virus which messed up the inhibitor. So when he investigated his uncle's death he was able to discover the secret too.
(To complete the picture, cops Rhodes and Amadeus Cho were investigating Peter's murder and the trail led them to the answer and their deaths last issue.)
Now Tony needs Kiri and Lila's Moving Fortress armours because they include the firewall that stops the inhibitor working. But he can't get to it from outside because the firewall itself is too good at its job.
But now Lila chips in to tell Tony and Arno that the battle has been a misdirection. While they fought, the girls were infecting the men's armours with a virus that weakened their systems. And the Starks fall.
Later the Thors come to take the Starks away. Jim Rhodes' deputy Harold Hogan becomes the new Marshall, Kiri becomes the new Baron and Lila is appointed as the new local Thor. Ex-Baroness Pepper Stark (who we haven't seen before in this series), who knew nothing of her husband's perfidy, stays to help an orderly handover. The disease remains uncurable, but Kiri and Lila devote themselves to at least improving the armour everyone has to wear.