"I know you will. Now the thing to do is to go at this thing systematically. Otherwise we'll be working around in a circle, and won't get anywhere. In the first place, let's set down what we do know. Then we'll put down what we don't know, and go after that."
"Put down what you don't know?" exclaimed Ned. "How are you going to put down a thing when you don't know it?"
"I mean we can put a question mark after it, so to speak. For instance we don't know where Mr. Damon is, but we want to find out."
"Oh, I see. Well, let's start off with the things we do know."
The two friends were at Tom's house by now, having come from Waterford in Tom's airship. After thinking over all the exciting happenings of the past few days, Tom remarked: "Now, Ned, for the things we do know. In the first place Mr. Damon is missing, and his fortune is about gone. There is considerable left to Mrs. Damon, however, but those scoundrels may get that away from her, if we don't watch out. Secondly, my airship was taken and brought back, with a button more than it had when it went away. Said button exactly matched one off Mr. Boylan's coat."
"Thirdly, Mr. Damon was either taken away or went away, in an airship--either in mine or someone else's. Fourthly, Mrs. Damon has received telephonic communications from the man, or men, who have her husband. Fifthly, Mr. Peters, either legally or illegally, is responsible for the loss of Mr. Damon's fortune. Now: there you are--for the things we do know."
"Now for the things we don't know. We don't know who has taken Mr. Damon away, nor where he is, to begin with the most important."
"Hold on, Tom, I think you're wrong," broke in Ned.
"In what way?"
"About not knowing who is responsible for the taking away of Mr. Damon. I think it's as plain as the nose on your face that Peters is responsible."