Mr Entwhistle looked at Dr Larraby thoughtfully.
He had had a lifetime of experience in summing people up. There had
 been frequent occasions on which it had been necessary to tackle a 
difficult situation or a delicate subject. Mr Entwhistle was an adept by
 now in the art of how exactly to make the proper approach. How would it
 be best to tackle Dr Larraby on what was certainly a very difficult 
subject and one which the doctor might very well resent as reflecting 
upon his own professional skill?
Frankness, Mr Entwhistle thought - or at least a modified 
frankness. To say that suspicions had arisen because of a haphazard 
suggestion thrown out by a silly woman would be ill-advised. Dr Larraby 
had not known Cora.
Mr Entwhistle cleared his throat and plunged bravely.
"I want to consult you on a very delicate matter," he said. "You 
may be offended, but I sincerely hope not. You are a sensible man and 
you will realise, I'm sure, that a - er - preposterous suggestion is 
best dealt with by finding a reasonable answer and not by condemning it 
out of hand. It concerns my client, the late Mr Abernethie. I'll ask you
 my question flat out. Are you certain, absolutely certain, that he died
 what is termed a natural death?"
Dr Larraby's good-humoured, rubicund middle-aged face turned in astonishment on his questioner.
"What on earth - Of course he did. I gave a certificate, didn't I? If I hadn't been satisfied -"
Mr Entwhistle cut in adroitly:
"Naturally, naturally. I assure you that I am not assuming anything
 to the contrary. But I would be glad to have your positive assurance - 
in face of the - er - rumours that are flying around."
"Rumours? What rumours?"
"One doesn't know quite how these things start," said Mr Entwhistle
 mendaciously. "But my feeling is that they should be stopped - 
authoritatively, if possible."
"Abernethie was a sick man. He was suffering from a disease that 
would have proved fatal within, I should say, at the earliest, two 
years. It might have come much sooner. His son's death had weakened his 
will to live, and his powers of resistance. I admit that I did not 
expect his death to come so soon, or indeed so suddenly, but there are 
precedents - plenty of precedents. Any medical man who predicts exactly 
when a patient will die, or exactly how long he will live, is bound to 
make a fool of himself. The human factor is always incalculable. The 
weak have often unexpected powers of resistance, the strong sometimes 
succumb."
"I understand all that. I am not doubting your diagnosis. Mr 
Abernethie was, shall we say (rather melodramatically, I'm afraid) under
 sentence of death. All I'm asking you is, is it quite impossible that a
 man, knowing or suspecting that he is doomed, might of his own accord 
shorten that period of life? Or that someone else might do it for him?"
Dr Larraby frowned.