‘You’re thinking, sir, that if the man wasn’t on the island, he couldn’t
have left the island, and according to the account of the interested parties he never was
on the island. Well, then the only explanation possible is that he was actually one of the
ten.’
The AC nodded.
Maine said earnestly:
‘We thought of that, sir. We went into it. Now, to begin with, we’re not
quite in the dark as to what happened on Soldier Island. Vera Claythorne kept a diary, so
did Emily Brent. Old Wargrave made some notes—dry legal cryptic stuff, but quite
clear. And Blore made notes too. All those accounts tally. The deaths occurred in this
order. Marston, Mrs Rogers, Macarthur, Rogers, Miss Brent, Wargrave. After his death
Vera Claythorne’s diary states that Armstrong left the house in the night and that Blore
and Lombard had gone after him. Blore has one more entry in his notebook. Just two
words. “Armstrong disappeared.”
‘Now, sir, it seemed to me, taking everything into account, that we
might find here a perfectly good solution. Armstrong was drowned, you remember.
Granting that Armstrong was mad, what was to prevent him having killed off all the
others and then committed suicide by throwing himself over the cliff, or perhaps while
trying to swim to the mainland?
‘That was a good solution—but it won’t do. No, sir, it won’t do. First
of all there’s the police surgeon’s evidence. He got to the island early on the morning of
August 13. He couldn’t say much to help us. All he could say was that all the people had
been dead at least thirty-six hours and probably a good deal longer. But he was fairly
definite about Armstrong. Said he must have been from eight to ten hours in the water
before his body was washed up. That works out at this, that Armstrong must have gone
into the sea sometime during the night of the 10th–11th—and I’ll explain why. We found
the point where the body was washed up—it had been wedged between two rocks and
there were bits of cloth, hair, etc., on them. It must have been deposited there at high
water on the 11th—that’s to say round about 11 o’clock a.m. After that, the storm
subsided, and succeeding high water marks are considerably lower.
‘You might say, I suppose, that Armstrong managed to polish off the
other three before he went into the sea that night. But there’s another point and one you
can’t get over. Armstrong’s body had been dragged above high water mark. We found it
well above the reach of any tide. And it was laid out straight on the ground—all neat and
tidy.
‘So that settles one point definitely. Someone was alive on the island
after Armstrong was dead.’
He paused and then went on.