She died there.
A case of some obscure blood poisoning.
It's got a long name, but I don't expect it would convey much to you.
Most uncommon in this country, fairly common among the natives in Egypt."
"So the doctor couldn't have poisoned her?"
"I don't know," said Battle slowly. "I've been chatting to a bacteriologist friend of mind - awfully difficult to get straight answers out of these people.
They never can say yes or no.
It's always 'that might be possible under certain conditions' - 'it would depend on the pathological condition of the recipient' - 'such cases have been known' - 'a lot depends on individual idiosyncrasy' - all that sort of stuff.
But as far as I could pin my friend down, I got at this - the germ, or germs I suppose, might have been introduced into the blood before leaving England.
The symptoms would not make their appearance for some time to come."
Poirot asked, "Was Mrs. Craddock inoculated for typhoid before going to Egypt? Most people are, I fancy."
"Good for you, Monsieur Poirot."
"And Doctor Roberts did the inoculation?"
"That's right.
There you are again - we can't prove anything.
She had the usual two inoculations - and they may have been typhoid inoculations for all we know.
Or one of them may have been typhoid inoculation and the other - something else.
We don't know.
We never shall know.
The whole thing is pure hypothesis.
All we can say is, It might be."
Poirot nodded thoughtfully.
"It agrees very well with some remarks made to me by Mr. Shaitana.
He was exalting the successful murderer, the man against whom his crime could never be brought home."
"How did Mr. Shaitana know about it then?" asked Mrs. Oliver.
Poirot shrugged his shoulders.
"That we shall never learn.
He himself was in Egypt at one time.
We know that, because he met Mrs. Lorrimer there.
He may have heard some local doctor comment on curious features of Mrs. Craddock's case - a wonder as to how the infection arose.
At some other time he may have heard gossip about Roberts and Mrs. Craddock.
He might have amused himself by making some cryptic remark to the doctor and noted the startled awareness in his eye - all that one can never know.
Some people have an uncanny gift of divining secrets.
Mr. Shaitana was one of those people.
All that does not concern us.
We have only to say - he guessed.
Did he guess right?"
"Well, I think he did," said Battle. "I've a feeling that our cheerful genial doctor wouldn't be too scrupulous.
I ve known one or two like him - wonderful how certain types resemble each other.
In my opinion he's a killer all right.
He killed Craddock. He may have killed Mrs. Craddock, if she was beginning to be a nuisance and cause a scandal.
But did he kill Shaitana?
That's the real question.
And comparing the crimes, I rather doubt it.
In the case of the Craddocks he used medical methods each time.
The deaths appeared to be due to natural causes.
In my opinion, if he had killed Shaitana, he would have done so in a medical way.
He'd have used the germ and not the knife."
"I never thought it was him," said Mrs. Oliver. "Not for a minute.
He's too obvious, somehow."