"When he sees Mrs. Monahan go up to the dining-room with X's breakfast, let him slip down-stairs and out through the yard of the vacant house. He will have a good five minutes or more while Mrs. M is arranging the things, etc. He will find plenty of ladders. Let him plant a short ladder against the back fence and drop into the X's yard. He cannot be seen from the X house unless Mrs. M just happens to be at the dining-room window, which is very unlikely. "I will enclose a little plan of the X house. Your man enters from the yard by door A, crosses kitchen and goes out by door Z into passage; opens door C into housemaid's closet, where he conceals himself until Mrs. M returns to kitchen. He then goes up the stairs D which brings him to the pantry above. There is a swing door into the dining-room. In front of this door is a tall leather screen. If he waits behind this screen until X gets fairly inside the room, he will be between him and the only exit. If X is already in the room he will have him dead to rights. "After the accident the chances of your man making a getaway are slim. The entrance hall to the house lies just in front of the dining-room. There are two stairs from the basement. If Monahan runs up through the pantry your man may get out by the front door, if he can open it in time, but if M comes up the front stairs he will meet him in the hall. However, I understood from you that the matter of the getaway was not of the first importance. "P.S. I have opened this to add that I have just learned X is booked to speak at the A.B.A. dinner at the Astor on Tuesday night. He will stay in town. If you think my plan is good enough you'll have to pull the trick Wednesday morning. The next time X stays in town the painters in the vacant house will be finished." Jack sat scowling at this document. Another ghastly assassination scheduled! His skin crawled with horror. How to discover the identity of the victim and warn him in time was the problem. It was planned for Wednesday morning---- Suddenly Jack sprang to his feet electrified. This was Wednesday morning. And it must be about nine-thirty now! He pulled out his watch with trembling fingers. The hands pointed to twenty minutes past nine. He had ten minutes! And he had yet to find out whom they planned to kill! He searched frantically among the other papers on the desk for a possible clue. He uncovered a card which had been removed from the index temporarily. A glance at it was sufficient. DELAMARE, WALTER DE COURCY. Of course! Delamare had threatened to defy the blackmailers! Delamare's house was on the North side of East Sixty-fourth Street: Delamare had been the principal speaker at the bankers' dinner the night before: Jack thought of the man's fine courage, his humanity, his humor, his unfailing kindness to himself, and turned sick with horror. "I have not time!" he groaned.