themselves into groups on the benches and pavements and ate and drank while discussing the matter.
A part of the night was spent in this way and nothing happened to reward the patience of the crowd, who began to wonder, somewhat wearily, if they would not do better to go home, seeing that Sauverand was in prison and that there was every chance that the fourth letter would not appear in the same mysterious way as the others.
And yet they did not go: Don Luis Perenna was due to come!
From ten o'clock in the evening the Prefect of Police and his secretary general, the chief detective and Weber, his deputy, Sergeant Mazeroux, and two detectives were gathered in the large room in which Fauville had been murdered. Fifteen more detectives occupied the remaining rooms, while some twenty others watched the roofs, the outside of the house, and the garden.
Once again a thorough search had been made during the afternoon, with no better results than before. But it was decided that all the men should keep awake. If the letter was delivered anywhere in the big room, they wanted to know and they meant to know who brought it. The police do not recognize miracles.
At twelve o'clock M. Desmalions had coffee served to his subordinates. He himself took two cups and never ceased walking from one end to the other of the room, or climbing the staircase that led to the attic, or going through the passage and hall. Preferring that the watch should be maintained under the most favourable conditions, he left all the doors opened and all the electric lights on.
Mazeroux objected:
"It has to be dark for the letter to come. You will
