Synopsis
It's Captain Marvel (Carol Danvers) doing the opening recap again. She reminds us that Anti-Man (Conner Sims) is in custody awaiting trial and that last issue she settled a diplomatic problem between Earth and the Shi'ar. They'd noticed some Cosmic Cube-like activity and she stopped Project PEGASUS experimenting with ISO-8 and some CC fragments. (Apparently they never detected the earlier actual Cosmic Cube involved in the Avengers: Standoff event.) But when she tried to inform the Shi'ar wormhole monitoring station she couldn't get through. (We know that they'd been killed by Thanos after he came through the wormhole from Exo-Space.)
But she also recalls the day the Ultimates were formed. She went to see Black Panther (King T'Challa of Wakanda) about dealing with cosmic threats. She suggested creating a proactive force, separate from the Alpha Flight defensive force that he created and she heads, that would go out and solve the big problems before they hit Earth. He agreed and suggested an old frenemy of his as another member.
So Carol found Blue Marvel (Dr Adam Brashear) in his undersea science fortress Kadesh Base. He thought it 'interesting' that T'Challa recommended him. CM said she knows he's no stranger to cosmic threats (eg Anti-Man's earlier crimes in the Adam: Legend Of The BM mini-series). He worried that the Ultimates sounded too much like the secretive Illuminati, but she assured him she wouldn't countenance that. He also wanted non-violent solutions but they compromised on 'where possible'. And he also suggested another member with power and strategic skills.
This time it's Spectrum (Monica Rambeau) who was with him in Sam Wilson's Mighty Avengers, and also used to be a different Captain Marvel). They joined forces to defeat Xarggu, The Mystery That Walks Like A Man, 1 of the Easter Island heads come to life. Monica accepted the offer and suggested Ms America Chavez as their 5th member. (MAC then got recruited in a tale in Avengers (2016) #0).
The US National Security Council got wind of the team and were worried. America Chavez might not even be loyal to this dimension, never mind the USA. Black Panther's loyalty belongs to his own country Wakanda and is a dubious ally. Monica Rambeau's a 'flake' and Adam Brashear's strong belief in democracy has always been trouble. The most moderate voice was worried about the cosmic scale the team plans to operate on. So they called on NSA operative Philip Nelson Vogt to keep an eye on them. And he told them his Troubleshooters were already on the job.
In the present we see the Inhuman precog Ulysses having a vision of Thanos killing people with a big gun. He reports to an audience of BP and CM alongside War Machine (James Rhodes) and other Inhumans Medusa, Crystal and Lockjaw. He had this vision before (in Civil War II #1) and awoke saying they had to call the Ultimates. So Medusa contacted Carol last issue and they all met at the Triskelion (in the Civil War Free Comic Book Day issue). Rhodey's there just because he came to visit Carol (in the FCBD). Ulysses says it'll happen in 3 hours time and describes the scene of his vision which CM recognises as Project PEGASUS.
They go inside and meet the other Ultimates. Colonel Danvers gets the facility evacuated and filled with SHIELD LMDs so as not to alert Thanos. She and Medusa call in whatever other members of A-Force they can get hold of (which turns out to be Dazzler and She-Hulk). Medusa can also get Human Torch (Johnny Storm) (because they're in a relationship at the time) and she'll have other Inhumans in reserve. CapM plans to absorb the energy from Thanos' gun to enable her to turn into Binary. Spectrum suggests they all then take it in turns to attack the foe, but they're not all used to working together so they must be careful not to get in each other's way.
The actual fight with Thanos was described in the CWII FCBD issue, including the fact that all extrapowerful items like Cosmic Cube fragments and ISO-8 have been removed. We get a 2-page summary in this issue showing how Spectrum's strategy (which wasn't described there) plays out and then fails. The tag-teaming ends when the Titan swings Medusa by her long hair to knock aside an incoming missile from War Machine which then detonates on She-Hulk. Shocked Rhodes is then killed by Thanos.
We then move on to CM's debriefing by SHIELD Director Maria Hill in the Triskelion. Carol describes the rest of the FCBD battle as everybody piled on Thanos until she took him out with a cosmic punch. But Rhodey's in the morgue. Hill has informed his family and left a message for his friend Tony Stark. (we don't get to see here as we do in CWII#1 that She-Hulk's paralysed and in a coma, but we do see Carol entering what I believe is Jennifer's room.)
We do see America Chavez blaming herself for Jim's death because she didn't fight well enough, and she's seeking comfort on the phone to her paramedic girlfriend (Lisa Halloran). Adam is trying to convince Monica that *she*'s not to blame. Rambeau thinks that she was too busy with her tactical plan that she overlooked an obvious strategy. She could have turned to light, gone through the Titan's eye and fried his brain. Adam assures his friend that she's not a god, she's human and humans make mistakes.
Then Iron Man makes a forceful landing on the roof and demands to see the Ultimates. (The confrontation plays out in CWII#1. When Stark learns that the battle that killed his friend was initiated by 1 of Ulysses' predictions he says he warned Danvers that they couldn't be trusted. And this sets up the 2 sides of *this* superhero Civil War.)
Epilogue 1:- Vogt reports on the events to the NSC. They don't understand how he's got through the SHIELD & Wakandan security at the Triskelion but he says his Troubleshooters are very good at what they do. The NSC are also worried about Thanos being held there, but he assures them the the Titan *can't* escape.
Epilogue 2:- Shackled Thanos is planning his next move.