Very interesting, Thanks. I first read this book in the late 70's and pretty much missed SO much of the clues....especially the obvious, Dr. Marsh dying in the field and becoming the half abo guide as the prison accounts attests to. Question. WHY does the "son" of the Master accuse Dr. Marsh of being an Abo? I comprehend he was impatient and wanted Marsh to leave so he could dispatch his dad-and-torturer. Profound meaning or cheap dramatic device?