Cable tries to prevent the state of Florida from executing an innocent girl, accused of murdering her parents, who also happens to be a mutant. She’s a psychic, and in her final hours she broadcasts to Cable all the bad stuff that’s happening over in the bad comic called Weapon X. Cable goes over to that comic now that his book is done.
And brings big guns. Those final panels indicate how completely predictable Cable is now. He’s returned to his old ways, which were usually not all that interesting. Sad.
Soldier X is a great example of how a creative vision to take a known character in a very different direction can go very wrong with the visionary team leaves. This series began as something different from anything else Marvel had ever done–and pretty much hasn’t ever done since, either. The series ended as a boring, pale imitation of where it started.