white bridge over the creek."

"Waiting for who?" asked Jack.

"For Mark, I guess; but I don't know. Anyhow, the note's for him."

"Hum! This is rather strange," mused Mark.

"What is it?" asked Jack.

"Why, this note. It says: 'It is important that I see you. I will wait
for you at the white bridge.' That's all there is to it."

"No name signed?" asked Jack.

"Not a name. But I'll just take a run down and see what it is. I'll not
be long. Much obliged, Dick."

The boy who had brought the note turned to leave the house, and Mark
prepared to follow. Jack said:

"Let me see that note."

He scanned it closely, and, as Mark was getting on his hat and coat,
for the night was chilly, his chum went on:

"Mark, if I didn't know, that we had left Axtell, the crazy machinist,
up on Mars, I'd say that this was his writing. But, of course, it's
impossible."