Ghostdrift

The final book of the Finder Chronicles, a hopepunk sci-fi caper described as Macgyver meets Firefly, by Hugo Award-winner Suzanne Palmer
"The kind of science fiction you'd get if Firefly and Pierce Brown's Red Rising had a baby-an adrenaline-packed, heist-filled ride with a heavy side of political intrigue." -BookPage (for Finder)
Fergus Ferguson, professional finder, always knew his semi-voluntary exile wouldn't last, but he isn't expecting a friend to betray him. One of the galaxy's most dangerous space pirates, Bas Belos, wants him, and what Belos wants, he gets. Belos needs help finding out what happened to his twin sister, who mysteriously disappeared at the edges of space years ago, and he makes Fergus an offer he can't refuse.
Mysterious disappearances and impossible answers are Fergus' specialties. After he reluctantly joins Belos and his crew aboard the pirate ship Sidewider, he discovers that Belos is being tracked by the Alliance. Seeking to stay one step ahead of the Alliance, Fergus and Belos find themselves marooned in the middle of the Gap between spiral arms of our galaxy, dangerously near hostile alien territory, and with an Alliance ship in hot pursuit.
That's just the beginning of the complications for Fergus' newest-and possibly last-job. The puzzle is much bigger than just Belos's lost sister, and the question of his future, retirement or not, depends on his ability to negotiate a path between aliens, criminals, and the most powerful military force he's ever encountered. The future of entire planets hangs in the balance, and it remains to be seen if it's too big for one determined man and his cranky cat.