le Mesurier Murder

Shortly before going off to look at some kind of ancient shrine or cairn (hidden in an incongruous urban setting between tower blocks) I brutally torture and kill John le Mesurier and his wife in their home. The sadism and viciousness of the act, which involves boiling water and the contents of their own cutlery drawer, doesn't appal me until afterwards.

'That's it', I think to myself later, 'There's no going back - I bear the Mark of Cain'.