Artificial Condition, by Martha Wells

Book two in the Murderbot Diaries follows on directly from All Systems Red, with the rogue security unit now on the run from both The Company that owns it and the benevolent former clients trying to help it. It hitches a ride with an unstaffed AI-driven cargo ship to a remote mining station, on a quest to discover the mystery of its past and the origins of its violent self-inflicted nickname. This involves reaching a level of trust with its powerful host and taking on a private security contract with a group of naïve researchers trying to regain their intellectual property from a criminal gang. Literally digging up the past raises as many questions as answers for the troubled SecUnit and the mission is complicated by its sense of obligation to protect its hapless clients, despite no imperative to do so. The tale is action-packed and funny and, although it has few organic parts and an enormous capacity for destruction, the SecUnit demonstrates more humanity than many of the actual humans it encounters.