“Yes, yes, that’s the point. I didn’t see it either until now. Don’t you understand? Bauerstein had it analysed⁠—that’s just it! If Bauerstein’s the murderer, nothing could be simpler than for him to substitute some ordinary cocoa for his sample, and send that to be tested. And of course they would find no strychnine! But no one would dream of suspecting Bauerstein, or think of taking another sample⁠—except Poirot,” I added, with belated recognition.

“Yes, but what about the bitter taste that cocoa won’t disguise?”

“Well, we’ve only his word for that. And there are other possibilities. He’s admittedly one of the world’s greatest toxicologists⁠—”

“One of the world’s greatest what? Say it again.”