What does it say that I read the opium chapter this night, after having woken up at 4:00AM (against all habit)?
I can see the temptation in using Sad Cypress as the anchor book for this chapter, and I'm glad Harkup gave an unambiguous spoiler warning this time around before proceeding to give away the final twist, in order to be able to address a compound that Christie uses in this novel (and which she only mentions by name in Poirot's final round-up of the suspects). Still, it's not like this is the only book by Christie where morphine plays a prominent role, and Harkup would have been able to do without a spoiler completely by choosing, say, By the Pricking of My Thumbs (which was likely inspired by one of the real life cases Harkup addresses anyway), discuss morphine, heroin / diamorphine and codeine exactly the way she does here, and then, without specifically identifying Sad Cypress, tag on a paragraph beginning with "In another book, the poisoner ..." -- and then proceed to describing the solution of Sad Cypress. Ah, well. But, as I said, at least this time around there's a clear spoiler warning ... which should absolutely be heeded by anybody who hasn't read Sad Cypress yet.
Notes on the previous chapters:
I'm now wondering whether the murderer in Ellis Peters's Monk's Hood would really have made it all the way to being found out by Brother Cadfael, a considerable time after the murder, without suffering the slightest effects of the drug himself.
And while I thought I couldn't possibly be more scared of both nicotine and opiates than I already am anyway, just reading about the chemistry involved all over again was a not-very-much-needed refresher of just how scary these really are. And, um, why kicking the habit (smoking) once and for all some 20 years ago was definitely the right thing to do.