In six hundred years the human race has spread to nearby stars, terraforming planets, creating habitats and all those things needed for life. The Erickson is the only builder class star ship, it creates huge stations that are the only thing that allow easy travel to the stars. It is about to leave for an unexplored star system. When they arrive they will be on their own, they must solve any problems they encounter or die.
On New Europe, a Painter who has lost hope for the future see's a job listing for the Erikson. He is deeply hurt but will heal, and in so doing becomes a man who can lead the Erikson to salvation after the worst happens.
On The Erikson a woman is deeply scarred, and later hurts herself even more. For she does not yet understand that you can not hold yourself responsible for those things you can not control.
Out beyond where any human has reached, in the deep, first contact of the worst kind is made. The hope of the Erickson will lie with the bravery and intelligence of two damaged people who must outwit and outfight a civilization who want the Erikson for themselves.
If you like hard science fiction like The Expanse or Artemis by Andy Weir you will love Humanity in the Deep.