A gifted Preservation linguist distrusts Murderbot yet risks himself to seek peaceful contact with armed strangers.
Thiago is a language expert from Preservation Alliance and a marital partner of Mensah's brother. Before the survey he voiced serious reservations about allowing Murderbot to provide security, even after Mensah told him she trusted the SecUnit with her life.
On the sea facility, Thiago violates the agreed security protocol to greet an unfamiliar boat without protective gear. After Murderbot takes a shot meant for him, he keeps the raider leader talking by offering supplies and pretending to struggle with the translation, buying time for Murderbot to infiltrate the vessel. Taken hostage, he still tries to de-escalate the confrontation and even offers himself as leverage. He survives because Murderbot refuses to permit hostages and Arada finds a safe shot.
Thiago is an adult man whose facial features, hair, build, and clothing are not yet described. During the confrontation he notably goes onto the observation deck without the protective gear required by the survey's security plan.
Thiago is the expedition's linguist, negotiator, and leading skeptic of Murderbot. His intelligence helps stall the raiders, but his disregard for security forces the SecUnit to rescue him repeatedly.