“Was it a serious theft?”

“It was rather; and it happened to be committed upon Cosmo Mornington, who was then living in the Province of Oran.  That was really what started our relations.”

There was a fresh silence; and Don Luis added: 

“Poor Cosmo!  That incident gave him an unshakable confidence in my little detective talents.  He was always saying, ’Perenna, if I die murdered’—­he had a fixed notion in his head that he would meet with a violent death—­’if I die murdered, swear that you will pursue the culprit,’”

“His presentiment was not justified,” said the Prefect of Police.  “Cosmo Mornington was not murdered.”

“That’s where you make a mistake, Monsieur le Prefet,” said Don Luis.

M. Desmalions gave a start.

“What!  What’s that?  Cosmo Mornington—?”

“I say that Cosmo Mornington did not die, as you think, of a carelessly administered injection, but that he died, as he feared he would, by foul play.”

“But, Monsieur, your assertion is based on no evidence whatever!”

“It is based on fact, Monsieur le Prefet.”

“Were you there?  Do you know anything?”

“I was not there.  A month ago I was still with the colours.  I even admit that, when I arrived in Paris, not having seen the newspapers regularly, I did not know of Cosmo’s death.  In fact, I learned it from you just now, Monsieur le Prefet.”

“In that case, Monsieur, you cannot know more about it than I do, and you must accept the verdict of the doctor.”

“I am sorry, but his verdict fails to satisfy me.”

“But look here, Monsieur, what prompts you to make the accusation?  Have you any evidence?”

“Yes.”

“What evidence?”

“Your own words, Monsieur le Prefet.”

“My own words?  What do you mean?”

“I will tell you, Monsieur le Prefet.  You began by saying that Cosmo Mornington had taken up medicine and practised it with great skill; next, you said that he had given himself an injection which, carelessly administered, set up inflammation and caused his death within a few hours.”

“Yes.”

“Well, Monsieur le Prefet, I maintain that a man who practises medicine with great skill and who is accustomed to treating sick people, as Cosmo Mornington was, is incapable of giving himself a hypodermic injection without first taking every necessary antiseptic precaution.  I have seen Cosmo at work, and I know how he set about things.”

“Well?”

“Well, the doctor just wrote a certificate as any doctor will when there is no sort of clue to arouse his suspicions.”

“So your opinion is—­”

“Maitre Lepertuis,” asked Perenna, turning to the solicitor, “did you notice nothing unusual when you were summoned to Mr. Mornington’s death-bed?”

“No, nothing.  Mr. Mornington was in a state of coma.”

“It’s a strange thing in itself,” observed Don Luis, “that an injection, however badly administered, should produce such rapid results.  Were there no signs of suffering?”