really, though its undisturbed trimness had made it serve all the purposes ofa wall. On the shore I found the loose rock fallen from its pedestal; and poor Harry Druce lay like a wreck underneath it. One arm was thrown round it in a sort of embrace as if he had pulled it down on himself; and on the broad brown sands beside it, in large crazy lettering, he had scrawled the words, "The Rock of Fortune falls on the Fool."

"It was the Colonel's will that did that," observed Father Brown. "The young man had staked everything on profiting himself by Donald's disgrace, especially when his uncle sent for him on the same day as the lawyer, and welcomed him with so much warmth. Otherwise he was done; he'd lost his police job; he was beggared at Monte Carlo. And he killed himself when he found he'd killed his kinsman for nothing."

"Here, stop a minute!" cried the staring Fiennes. "You're going too fast for me."

"Talking about the will, by the way," continued Father Brown calmly, "before I forget it, or we go on to bigger things, there was a simple explanation, I think, of all that business about the doctor's name. I rather fancy I have heard both names before somewhere. The doctor is really a French nobleman with the title of the Marquis de Villon. But he is also an ardent Republican and has abandoned his title and fallen back on the forgotten family surname.