So, when we last left Murderbot, it had decided to part ways with Dr. Mensah and her crew and go on some adventures with ART and its crew for a while. Also, Muderbot had another, newly liberated SecUnit following it around. But apparently this book takes place between the series of novellas and the full-length novel that came out last year, because when it starts, there’s no ART, no other rogue SecUnit, and Muderbot is back to hanging out with Dr. Mensah and friends.
Instead, Murderbot is still with Dr. Mensah and friends on Preservation Station looking at a dead body and wondering if this is Graycris making its next move against them.
As it turns out, it’s not GrayCris, but the Corporate Rim is involved. By doing some sleuthing, Murderbot and its friends (and reluctant coworkers … for now) find out that the murder victim was involved in an elaborate sort of underground railroad to smuggle corporate slaves out of the Corporate Rim and into the Preservation Alliance.
You know how sharecroppers were lured to America with the promise they would work off the cost of their transport and then they could go do whatever they want, but in reality their “employers” always messed with the numbers to make it seem like the workers were in debt and it ended up being more like slavery than any kind of real employment? The same thing is happening in the Corporate Rim, but it goes on for generations. The kids of those sharecroppers are also forced to work for little-to-no pay and their kids are forced to work, etc.
So some of them just decide they’ve had enough and that it’s time to GTFO. The murder victim is one of the people who helps those people escape, and once Murderbot and friends realize what he was up to, they manage to rescue the victim’s latest shipment of refugees, who are in the process of being abducted to be taken back to the Corporate Rim. Unfortunately, there’s no way of knowing what else the murder victim was doing for the space underground railroad or how many other refugees are out there, unaware that their next contact no longer exists.
In any case, they manage to rescue a dozen or so humans and Murderbot only gets shot once by one of the people it’s actively trying to rescue.
Other than that, it’s a pretty typical murder mystery with your cyborg detective trying to keep stupid humans safe with a murderer on the loose, rescue humans who shoot at it, and solve a murder. There’s a big showdown with the murderer at the end, a pretty epic robot battle, and no other humans get killed. All in a day’s work for your friendly, sarcastic cyborg.