He gnawed his lip, drummed his fingers upon the table, and showed every other symptom of acute impatience.

So great was his emotion, that I felt sincerely sorry for him, while the two detectives smiled derisively, by no means displeased at this check which he had met.
"It can't be a coincidence," he cried, at last springing from his chair and pacing wildly up and down the room; "it is impossible that it should be a mere coincidence.

The very pills which I suspected in the case of Drebber are actually found after the death of Stangerson.

And yet they are inert.

What can it mean?
Surely my whole chain of reasoning cannot have been false.