"Just so. In a Southampton boarding-house, in a room with a locked
door, this man was stung by a cobra. To add a little mystification to
the limpid simplicity of the affair, when the door was opened there was
no sign of any cobra. It couldn't have got out through the door,
because the door was locked. It couldn't have got out of the window,
because the window was too high up, and snakes can't jump. And it
couldn't have gotten up the chimney, because there was no chimney. So
there you have it."

He looked at Oakes with a certain quiet satisfaction. It had come to
his ears that Oakes had been heard to complain of the infantile nature
and unworthiness of the last two cases to which he had been assigned.
He had even said that he hoped some day to be given a problem which
should be beyond the reasoning powers of a child of six. It seemed to
Mr. Snyder that Oakes was about to get his wish.

"I should like further details," said Oakes, a little breathlessly.

"You had better apply to Mrs. Pickett, who owns the boarding-house,"
Mr. Snyder said. "It was she who put the case in my hands. She is
convinced that it is murder. But, if we exclude ghosts, I don't see how
any third party could have taken a hand in the thing at all. However,
she wanted a man from this agency, and was prepared to pay for him, so
I promised her I would send one. It is not our policy to turn business
away."

He smiled wryly. "In pursuance of that policy I want you to go and put
up at Mrs. Pickett's boarding house and do your best to enhance the
reputation of our agency. I would suggest that you pose as a ship's