Then Ted found another message from them near the front door.
It was as follows:
"TED STRONG AND OTHERS: You think you know who committed the mysterious robberies, but you are on the wrong track. You will never find out, while your secrets are known to us. This is warning number two. The third and last will come soon; then look out.
"THE FLYING DEMONS."
"Now, why in the world do they call themselves the Flying Demons?" asked Ted reflectively, as they were reading the second screed from their enemies. "It seems to me that there is the secret of the whole thing. You never can tell what a pack of boys like that are going to do. They are more to be feared than older criminals, for they have no judgment, and will rush into the most reckless things just to show off before one another."
"Pay no attention to them," advised Stella. "That's what I think they are doing now—showing off. I doubt if they think they can frighten us, but they are afraid of us."
"Oh, by the way," said Ted, suddenly thinking of something. "You remember I looked at the watermark on that first warning we received from these terrible demons. Well, this screed has the same mark—'Griffin Bond.' When I was in town to-day I went into the bank. Old man Creviss was behind the counter, and that precious son of his was beside him. I had a check cashed, and Mr. Creviss asked me why we didn't keep our bank account there. I told him we had thought something about it, but I didn't mention that we had decided not to. Then I asked him for a couple of sheets of paper on which to write a note, and he handed them to me. I took them to the window and held them up to the light to see the watermark."
"And what was it?" asked Stella eagerly.
"The griffin."
"Then the paper on which these things were written came from the bank?"