As you can imagine, we keep a close eye on all our medicines, especially the more dangerous ones, and I was particularly concerned by its disappearance.’ ‘What was the drug?’ ‘Physostigmine. It’s actually a cure for belladonna poisoning and I’d had to get some in for Henrietta Osborne, the vicar’s wife.
Redwing tells Pünd about the poison, and that she'd told Mary. Also interesting that Henrietta Osborne came into the surgery the day it went missing AND she was the reason Redwing had it in the first place. Undoubtedly, Redwing told her how dangerous it could be in larger doses?
But also, didn't we get impression that someone had taken the poison? Was it Clarissa?