“You’re mad,” I said.

 

“No,” said Poirot placidly. “I am not mad. It was the little discrepancy in time

that first drew my attention to you—right at the beginning.”

 

“Discrepancy in time?” I queried, puzzled.

 

“But yes. You will remember that every one agreed—you yourself included—that it

took five minutes to walk from the lodge to the house—less if you took the short

cut to the terrace. But you left the house at ten minutes to nine—both by your

own statement and that of Parker, and yet it was nine o’clock as you passed

through the lodge gates. It was a chilly night—not an evening a man would be

inclined to dawdle; why had you taken ten minutes to do a five-minutes’ walk?

All along I realized that we had only your statement for it that the study

window was ever fastened. Ackroyd asked you if you had done so—he never looked

to see. Supposing, then, that the study window was unfastened?

 

Would there be time in that ten minutes for you to run round the outside of the

house, change your shoes, climb in through the window, kill Ackroyd, and get to

the gate by nine o’clock? I decided against that theory since in all probability

a man as nervous as Ackroyd was that night would hear you climbing in, and then

there would have been a struggle. But supposing that you killed Ackroyd _before_

you left—as you were standing beside his chair? Then you go out of the front

door, run round to the summer-house, take Ralph Paton’s shoes out of the bag you

brought up with you that night, slip them on, walk through the mud in them, and