But there was no answer, so Holmes pushed open the door, turning the gas half on and lighting it.
"This afternoon," declared Greg, "I dropped a stub of a pencil in our room.

It fell on the bricks of the floor of the fireplace, and rolled into the space between two of the bricks.

In getting that pencil out I got on the back of my hand the smear that you all saw.
"Fellows, I've been thinking for weeks and months about that smear on the back of Mr.Dodge's hand.

When I saw the one on the back of my own hand it occurred to me at once how Mr.Dodge might have got that black spot on his hand.

It came over me, all in a flash.
I knew that Brayton and Mr.Dodge would be out of the way this evening at the hop.