‘Don’t you worry, Dr Redwing,’ Mary had said. ‘You leave it with me for a day or two. As a matter of fact, I may have one or two ideas . . .’ That was what she had said. At the same time there had been a look on her face which wasn’t exactly sly but which was knowing, as if she had seen something and had been waiting to be consulted on this very matter. And now she was dead.
Mary knew about the missing poison and may have taken that information to an unknown someone.
