"He's used two different kinds of pens," said Inspector Chippenfield. "Look at the difference in the thickness of the letters." "The sooner he writes again the better," said Rolfe. "I am curious to know what he'll say next." "My idea is to find out who he is and make him speak," said the inspector, "Speaking is quicker than writing. I could frighten more out of him in ten minutes than he would give away voluntarily in a month of Sundays." Again Rolfe had to admit that his chief's plan to get at the truth was an ideal one. "Have you any idea who he is?" he asked. Inspector Chippenfield had brought his methods too near to perfection to make it possible for him to fall into an open trap. "I won't be very long putting my hand on him," he said. "But this thing has been in the papers," said Rolfe. "Don't you think the murderer will bolt out of the country when he knows his mate is prepared to turn King's evidence against him?" "Ah," said Inspector Chippenfield, "I haven't adopted your theory." "Then you think that the man who wrote this note knew of the murder but doesn't know who did it?" "Now you are going too far," said Inspector Chippenfield. The inspector was so wary about disclosing what was in his mind in regard to the letter that Rolfe, who disliked his chief very cordially, jumped to the conclusion that Inspector Chippenfield had no intelligible ideas concerning it. "If it was burglars they took nothing as far as we can ascertain up to the present," said Inspector Chippenfield after a pause. "They were surprised to find anyone in the house. And after the shot was fired they immediately bolted for fear the noise would attract attention." "What knocks a hole in the burglar theory is the fact that Sir Horace was fully dressed when he was shot," said the inspector. "Burglars don't break into a house when there are lights about, especially after having been led to believe that the house was empty." "So you think," said Rolfe, "that the window was forced after the murder with the object of misleading us." "I haven't said so," replied the inspector. "All I am prepared to say is that even that was not impossible." "It was forced from the outside," continued Rolfe. "I've seen the marks of a jemmy on the window-sill. If it was forced after the murder the murderer was a cool hand." "You can take it from me," exclaimed Inspector Chippenfield with unexpected candour, "that he was a cool hand. We are going to have a bit of trouble in getting to the bottom of this, Rolfe." "If anyone can get to the bottom of it, you can," said Rolfe, who believed with Voltaire that speech was given us in order to enable us to conceal our thoughts. Inspector Chippenfield was so astonished at this handsome compliment that he began to think he had underrated Rolfe's powers of discernment. His tone of cold official superiority immediately thawed.