Rank has become flexible and inventive in his techniques for eliminating pesky relatives, which will make him hard to detect as a killer. so far, things look like "accidents", or, at worst, suspicious but not leading back to him. but I don't know how the cumulative effect of heirs to the earldom turning up deceased is not going to keep authorities, and anyone else, from smelling a homicidal rat.
in terms of mood, the book does now feel like a bit of a Dark Comedy, though the style is only occasionally overt in conveying that impression. as Rank narrates this bleak memoir, he actually exhibits mixed emotions as they resonated in his earlier, busier self--but what it seems to boil down to is "once I started upon my path, no matter the regrets or the sleepless nights, there was never a good reason to stop.".
this book is looking, for now, at an extremely high rating from me, pre-dating such works as The Talented Mr. Ripley, and Pop. 1280, by decades. of course, The Invisible Man came earlier, but that's slightly different thanks to the SF content.