"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 the hilt of the dagger, intending to withdraw it, but could not bring herself to use the necessary force." "Why didn't she call out?" demanded Thornton. "It seems to me----" "There is no accounting for actions arising out of sudden emotions. Lady Eileen Meredith is as extraordinary a woman in her way as the Princess Petrovska in hers. She had found a man murdered in her lover's study--and she may have had a shrewd idea of the reason why she was summoned there. You follow me? Probably as she stood there, hesitating what to do, Grell returned. I think it likely that he stood by the door, took in the situation quietly, and stole away with the impression that she had killed Goldenburg. If she was bending over the dead man, that was what he might naturally think. "It is likely that he would make up his mind in an instant. To him the fact that she had raised no outcry would be significant of her guilt. She, let us suppose, stole away, having made no attempt to examine the body closely and not daring to summon any one, for fear that Grell should prove to be the murderer. He watched her go, already determined to destroy the scent by taking the blame on his own shoulders.