otting-pad, which corresponded to those on
the dagger, and also to those on the typewritten warning which Ivan sent
me. The only plausible motive for Grell's actions, if he was not guilty
himself--and that we are fairly certain of--was his desire to shield
some one else. There could be only one person for whom he was willing
to make such a sacrifice--Lady Eileen Meredith."

"Yes, I understand that. But the finger-prints on the warning?"

"They puzzled me for a while. But that was made clear when I talked to
Ivan. He had typed it on the blank half-sheet of a letter given to him
by Grell. That letter--it is only an assumption of mine--was one that
had been written to Grell by Lady Eileen. That clears that point."

"Still, I don't see how you have anything against Lola more than you had
before."

"There is this. The weak link in the chain of evidence against Lady
Eileen Meredith was the lack of motive. That was why I did not have her
arrested immediately I found that it was her finger-prints upon the
dagger. The strongest point against the Princess is the motive. She was
married to Goldenburg, but was not on the best of terms with him. She
was bought by Grell to play the part of Delilah to the blackmailer. My
theory is this--bear in mind that it is only a theory at the moment.
Grell, for some reason, left her alone with Goldenburg in his study.
There was a quarrel, and she stabbed him. It must have been all over in
a few seconds, and there was no outcry. You will remember that the body
was found on a couch in a recess, and you may have noted that curtains
could be drawn across to shield it from the rest of the room. Petrovska
may have drawn the curtains and slipped away before Grell returned. She
is a woman of nerve and would at once set about manufacturing an
alibi."

"All this is very ingenious, Foyle," remarked Thornton, "but I don't
know that it sounds altogether convincing to me."

"It is pure surmise, Sir Hilary. Its chief merit is that it fits the
facts. Of course, Lady Eileen may be the murderess after all. I am only
working out an alternative. To carry it on a bit further. When Lady
Eileen came, Ivan showed her up to the room. No one answered his knock.
She went in and shut the door after her. It is my idea that there was no
one in there when she discovered the dead man. She was dumbfounded at
first, and probably the body being in the shade did not permit her to
see the face clearly. She placed her hand on t