Penelope examined:  Took a lively interest in the painting on the door, having helped to mix the colours.  Noticed the bit of work under the lock, because it was the last bit done.  Had seen it, some hours afterwards, without a smear.  Had left it, as late as twelve at night, without a smear.  Had, at that hour, wished her young lady good night in the bedroom; had heard the clock strike in the “boudoir”; had her hand at the time on the handle of the painted door; knew the paint was wet (having helped to mix the colours, as aforesaid); took particular pains not to touch it; could swear that she held up the skirts of her dress, and that there was no smear on the paint then; could not swear that her dress mightn’t have touched it accidentally in going out; remembered the dress she had on, because it was new, a present from Miss Rachel; her father remembered, and could speak to it, too; could, and would, and did fetch it; dress recognised by her father as the dress she wore that night; skirts examined, a long job from the size of them; not the ghost of a paint-stain discovered anywhere.  End of Penelope’s evidence—­and very pretty and convincing, too.  Signed, Gabriel Betteredge.

The Sergeant’s next proceeding was to question me about any large dogs in the house who might have got into the room, and done the mischief with a whisk of their tails.  Hearing that this was impossible, he next sent for a magnifying-glass, and tried how the smear looked, seen that way.  No skin-mark (as of a human hand) printed off on the paint.  All the signs visible—­signs which told that the paint had been smeared by some loose article of somebody’s dress touching it in going by.  That somebody (putting together Penelope’s evidence and Mr. Franklin’s evidence) must have been in the room, and done the mischief, between midnight and three o’clock on the Thursday morning.

Having brought his investigation to this point, Sergeant Cuff discovered that such a person as Superintendent Seegrave was still left in the room, upon which he summed up the proceedings for his brother-officer’s benefit, as follows: 

“This trifle of yours, Mr. Superintendent,” says the Sergeant, pointing to the place on the door, “has grown a little in importance since you noticed it last.  At the present stage of the inquiry there are, as I take it, three discoveries to make, starting from that smear.  Find out (first) whether there is any article of dress in this house with the smear of the paint on it.  Find out (second) who that dress belongs to.  Find out (third) how the person can account for having been in this room, and smeared the paint, between midnight and three in the morning.  If the person can’t satisfy you, you haven’t far to look for the hand that has got the Diamond.  I’ll work this by myself, if you please, and detain you no longer-from your regular business in the town.  You have got one of your men here, I see.  Leave him here at my disposal, in case I want him—­and allow me to wish you good morning.”