Action ou Vérité (Les Escales noires)

The pacing in 'Truth or Dare' is relentless, and I'm curious about the techniques used to build tension without feeling overdone. Did the author intentionally leave clues for readers to piece together?

The characters often face morally gray situations that made me question what I would do in their place. How does the author navigate creating empathy for flawed characters?

The shifting viewpoints added layers to the mystery, but I wonder if that was planned from the start or a later choice to enhance suspense.