Thank you! I haven't read much Christie, or much mystery in general really, but yes -- there's something inherently disturbing about the "dead person of the week" plot framework. And TV is especially limiting, because the 45-minute format means you really don't have much time to dwell on the victim, except insofar as their life constitutes a set of clues for the detective to assemble into a picture of their killer. Novels, even fairly short ones, have more leeway for that -- though not all of them necessarily use it.