Planetary explorers are required by the Company to have Security Units (SecUnits) with them. A SecUnit is an android, partially organic, partially a weaponized suit of armor, supposedly well equipped to handle any situation, and it's one of those SecUnits who narrates All Systems Red (The Murderbot Diaries), a new novella from Martha Wells.
SecUnits don't have names, but this one is self-named Murderbot because Murderbot has hacked the governing system and has free will. Murderbot could have become a serial killer, but has chosen instead to download thousands of hours of video entertainment and is particularly fond of a show called Sanctuary Moon. What could possibly go wrong?
Plenty, of course, including the murder of every member of a much larger exploratory team on the planet. Murderbot doesn't particularly like the humans s/he works with, but a job's a job, and the action's pretty much nonstop after the murders are discovered. Murderbot goes well above and beyond the expected duties, and soon most of the humans on the team begin to suspect that Murderbot is pretty much a human, too. And they're right, but Murderbot can't stand to be treated as an equal, preferring to cover up at all times or even be in a different room if possible. So within the action story there's also the story of the developing relationship between Murderbot and the team members and Murderbot's growing realization that there's more to life than being a SecUnit.
All Systems Red is great SF entertainment, with a thoroughly engaging narrator, humor, action, and heart. Check it out.