and a deep scar on his right cheek stood on the threshold looking at
them in dazed surprise. For an instant only had he lost his control.
The next second he was in his room again, slamming the door behind
him. But it was too late. Amster's foot was already in the crack
of the door and he pushed it open to let Muller enter. "Well done,"
cried the latter, and then he turned to the man in the room. "Here,
stop that. I can fire twice before you get the window open."

The man turned and walked slowly to the centre of the room, sinking
down into an arm-chair that stood beside the desk. Neither Amster
nor Muller turned their eyes from him for a moment, ready for any
attempt on his part to escape. But the detective had already seen
something that told him that Langen was not thinking of flight.
When he turned to the desk, Muller had seen his eyes glisten while
a scornful smile parted his thin, lips. A second later he had let
his handkerchief fall, apparently carelessly, upon the desk. But
in this short space of time the detective's sharp eyes had seen a
tiny bottle upon which was a black label with a grinning skull.
Muller could not see whether the bottle was full or empty, but now
he knew that it must hold sufficient poison to enable the captured
criminal to escape open disgrace. Knowing this, Muller looked with
admiration at the calmness of the villain, whose intelligent eyes
were turned towards him in evident curiosity.

"Who are you and who else is here with you?" asked the man calmly.

"I am Muller of the Secret Service," replied his visitor and added,
"You must put up with us for the time being, Mr. Egon Langen. The
police commissioner is occupied with your step-sister, whom you
were about to murder."