Natural Causes by Eric Chappell

Vincent is from Exodus, a euthanasia group that assists people in suicide and his discovery of a tasteless, colourless poison makes him ideal for the job. When he is invited to Walter Bryce’s country mansion to assist in the disposal of Walter’s wife Celia he senses something is wrong.

Why are all the suicide notes typed and not signed by Celia? What is the role of Walter’s attractive secretary Angie? Why has Withers been sent for from the Samaritans to dissuade characters from suicide?

You'll kill yourself laughing...