"I received your telegram and here I am," said a gentleman with a grey moustache, who entered my study, dressed in a dark-brown frock-coat and a wide-brimmed hat, with a red ribbon in his buttonhole. "What's the matter?" Had I not been expecting Arsene Lupin, I should certainly never have recognized him in the person of this old half-pay officer: "What's the matter?" I echoed. "Oh, nothing much: a rather curious coincidence, that's all. And, as I know that you would just as soon clear up a mystery as plan one...." "Well?" "You seem in a great hurry!" "I am ... unless the mystery in question is worth putting myself out for. So let us get to the point." "Very well. Just begin by casting your eye on this little picture, which I picked up, a week or two ago, in a grimy old shop on the other side of the river. I bought it for the sake of its Empire frame, with the palm-leaf ornaments on the mouldings ... for the painting is execrable." "Execrable, as you say," said Lupin, after he had examined it, "but the subject itself is rather nice. That corner of an old courtyard, with its rotunda of Greek columns, its sun-dial and its fish-pond and that ruined well with the Renascence roof and those stone steps and stone benches: all very picturesque." "And genuine," I added. "The picture, good or bad, has never been taken out of its Empire frame. Besides, it is dated.... There, in the left-hand bottom corner: those red figures, 15. 4. 2, which obviously stand for 15 April, 1802." "I dare say ... I dare say.... But you were speaking of a coincidence and, so far, I fail to see...." I went to a corner of my study, took a telescope, fixed it on its stand and pointed it, through the open window, at the open window of a little room facing my flat, on the other side of the street. And I asked Lupin to look through it. He stooped forward. The slanting rays of the morning sun lit up the room opposite, revealing a set of mahogany furniture, all very simple, a large bed and a child's bed hung with cretonne curtains. "Ah!" cried Lupin, suddenly. "The same picture!" "Exactly the same!" I said. "And the date: do you see the date, in red? 15. 4. 2." "Yes, I see.... And who lives in that room?" "A lady ... or, rather, a workwoman, for she has to work for her living ... needlework, hardly enough to keep herself and her child." "What is her name?" "Louise d'Ernemont.... From what I hear, she is the great-granddaughter of a farmer-general who was guillotined during the Terror." "Yes, on the same day as Andre Chenier," said Lupin. "According to the memoirs of the time, this d'Ernemont was supposed to be a very rich man." He raised his head and said, "It's an interesting story.... Why did you wait before telling me?" "Because this is the 15th of April." "Well?" "Well, I discovered yesterday--I heard them talking about it in the porter's box--that the 15th of April plays an important part in the life of Louise d'Ernemont." "Nonsense!"