Okay, so this is a topic that really digs under the skin of a thriller. Hostage situations are basically pressure cookers for the psyche, and some authors use that to examine trauma in ways that linger long after you finish reading. I keep thinking about 'The Cellar' by Minette Walters. It’s brutal, but the way it charts the mental disintegration and the fragile alliances between captives is horrifyingly precise. It’s less about the physical escape and more about the mental map the main character builds to stay sane, mapping the captor’s routines, finding tiny rebellions. The survival strategy becomes a kind of internal architecture.
Another one that haunts me is 'Room' by Emma Donoghue, obviously. Told from the kid’s perspective, the trauma is baked into the very language he uses to describe his world. His survival strategy is that he doesn’t even know he’s a hostage, which is its own kind of psychological protection. The real trauma exploration kicks in after the escape, which is something a lot of books skip. The adjustment to the outside world is its own terrifying ordeal.
For a colder, more procedural take, Thomas Harris’s 'Black Sunday' has a section with a hostage on the blimp that gets into the numbness and tactical dissociation. The character mentally recites flight manuals to stay grounded. It’s a different flavor of coping, less emotional and more mechanically obsessive, which feels true for certain personalities under duress.