"There are poisons--known to experts--which will destroy life almost to a given minute, and of which the most skilful pathologist and expert will not be able to find a single trace.

Now, please, understand my position--I say, it is quite possible, quite likely, quite in accordance with what I have seen, that this unfortunate gentleman died of heart failure brought about by even such an ordinary exertion as his stooping forward to untie his shoe-lace, but--I also think it likely that his death resulted from poison, subtly and cunningly administered, probably not very long before his death took place.

And if I only knew--" He paused at that, and looked searchingly and meaningly at Marshall Allerdyke before he continued.

And Allerdyke looked back with the same intentness and nodded.
"Yes--yes!" he said.

"If you only knew--?
Say it, doctor!" "If I only knew if there was any reason why any person wished to take this man's life," responded Dr.Orwin, slowly and deliberately.