"Good," cried Mr. Cook. "We'll hurry and you may be sure we'll be ready any time you call on us." They left the police station and were soon on their way home. Arriving at the house, Hugh and Mr. Cook got out, and Bob drove the car down to the garage. There he found Heinrich seated on a box in one corner intently studying a sheet of paper he held in his hand. "What you got, Heinie?" asked Bob cheerily. "A love letter!" Heinrich looked up at Bob, a curious expression in his pale blue eyes. He made no comment, however, and presently returned to the perusal of the paper he held. "What is it?" demanded Bob, impressed by the chauffeur's manner. An air of gloom seemed to pervade the garage, even the dog, the cat, and the parrot appeared to be affected by it. The dog stood listlessly by his master's side, the cat walked idly up and down, and the bird failed to greet Bob with his usual cheery "How do"; he sat limply on his perch, his feathers ruffled, and muttered to himself. Heinrich handed the paper to Bob. It was a sheet evidently torn from a pad and in a large scrawling hand was written the following: "We warned your boss to keep his car at home; now tell him to keep his son there, too." No name was signed and Bob turned the paper over and looked at the opposite side. A picture of an alligator was drawn there. Bob recognized the sheet as similar to the one that he and Hugh had found in the deserted house and the detective had taken from them; apparently it had been torn from the same pad. "Where did you get this, Heinie?" he demanded. "I go up to the house to see Lena," said Heinrich. "That is maybe a half-hour ago. I only stay there a few minutes and when I come back here is this." "Lying on the floor?" "Yes." "Have you no idea who sent it?" "How should I?" exclaimed Heinrich. "Somebody must have slipped in here while you were absent and left it," said Bob. "There are queer things happening around here these days, Heinie." "There is," the chauffeur admitted solemnly. "Do you mind if I keep this paper?" "No." Bob started out. "You better do as that says, too," exclaimed Heinrich earnestly. "You would not want anything to happen to you." "I'm not afraid," said Bob soberly. "You know, Heinie," he continued, "some people are trying to blow up things around here. Some of your countrymen, and we can't let them do anything like that, you know." Heinrich seemed much perturbed at this. "So?" he exclaimed his eyes wide. "Yes," said Bob, "and it's men like you who ought to stop them. You men who were Germans but are now Americans, could do yourselves a good turn if you did. Some people of German blood are under suspicion nowadays and if you showed that you were loyal to the United States it would be a good thing for you. Not that I mean to say we are suspicious of _you_," Bob hastened to add. This speech of Bob's seemed to offer a new line of thought to Heinrich who merely stared at Bob and said nothing.