Synopsis
The Mighty Avengers (Ares, Ms Marvel, Wasp and Wonder Man) are fighting Iron Man's collection of old armours animated by Ultron when Ares suddenly has a bright idea. He steers the IM armour he's currently riding away from the battle outside Avengers Tower.
Inside the Watchtower on top of Avengers Tower Sentry is cradling the dead body of his wife Lindy. Ultron, wearing the female body it formed out of Tony Stark and his armour, reminds Bob Reynolds that she warned him to leave Earth (in #3). Sentry punches her out of the building and they start another of their mid-air fights.
Ares flies his Iron Man to the crashed SHIELD helicarrier currently commanded by Avenger Black Widow. He finds Henry Pym and says he wants to be shrunk very small (to subatomic level suggests Pym) and fired into Ultron with a computer virus to disable her. Pym confirms that they're working on such a virus but it isn't ready yet.
Pym and Natasha Romanoff tell Ares to go back to the fight to keep Ultron distracted while they finish the virus. But the God of War insists that it is Ultron who is distracting them. She obviously has some bigger plan she's progressing. But he also reminds them that her current incarnation is built from Tony's armour and human body - surely she has inherited weaknesses from that.
Hank Pym latches on to that thought and turns to the AI in the original Iron Man armour that they are using as the operating system and power source for the helicarrier (after Ultron's hack and EMP ruined the previous ones in the last 2 issues). He asks if if the AI has any info about the Commodore 64 in its files. When the AI says no he asks SHIELD to rustle up such a machine.
Full power comes back after the EMP along with communication with the outside world. Only to reveal that nuclear missile bases all over the world are experiencing repetitive hacking attempts.
Maria Hill chooses this moment to recover from her concussion (#3) and takes command back from Black Widow. She suggests that Ares go fetch Wasp and she can deliver the virus to Ultron. Ares counters that Ultron will be ready for Wasp or Ant-Man. But she won't be expecting him.
Meanwhile the Sentry/Ultron grudge match continues, with the Iron Man suits running interference for the robot while she at last gains control of a missile, and launches it. It a US rocket rising from Florida, and Natasha contacts Carol Danvers to intercept it. Hill tells her how to mess up the trajectory control system, and the last we see is Ms Marvel riding the rocket up into the atmosphere before it explodes.
I think the blast distracts Sentry because Ultron is able to punch him to Pittsburgh. But Wonder Man takes up the fight and uses his ionic energy to scramble Ultron's brains. But the robot shrugs off the attack as Ant-Man approaches. (All the while she is continuing her hacking attempts on other missile sites.)
Henry Pym asks her to stop. Humanity will surrender if she'll give them time to evacuate people to safety (off Earth?). Ultron says she doesn't intend to kill him. She wants her creator to see the end result of his efforts.
But the AI-driven old armour has sneaked up behind her, hidden in the crowd of later armours. Even as Ultron realises this drone isn't under her control and destroys it, the miniaturised Ares on a SHIELD sky-sled has entered her mouth.