Under a Winter Sun
Worldburner book 2
It simply reads "Project Jotun".
Nobody knows what it means but all signs indicate the Goliaths are planning something. Something big. And they have help.
This scares the secretive immortal Terran overlords enough to request the aid of their old nemesis, Asher Perez, and propose a truce until the mystery has been solved.
It's not so much the mystery that convinces Perez to take the job. It's more that he will get to work very closely with a highly competent all-women special ops team.
And he will get to meet his old friend Thorfinn Wagner again.
Had he known what is about to hit the fan, he would have stayed home, stashed up on cheap whisky and drunk himself senseless in preparation for the end of the world.