while I am rather amazed at the news of the fire, for I did not
think the plotters would be so bold as that, it is in line with
what I expected, and what we suspected in Washington."

"And that was--what?" asked Tom.

"The existence of a well-laid plot, not only against our
government, but against you!"

"And why have they singled me out?" Tom demanded.

"I might as well tell it from the beginning," the officer went
on. "As long as you have not received any official warning from
Washington you had better hear the whole story. But are you sure
you had no word?"

"Well, now, I won't be so sure," Tom confessed. "I have been
working very hard, the last two days, making some intricate
calculations. I have rather neglected my mail, to tell you the
truth.

"And, come to think of it, there were several letters received
with the Washington postmark. But, I supposed they had to do with
some of my patents, and I only casually glanced over them. There
was one letter, though, that I couldn't make head or tail of."

"Ha! That was it!" cried the lieutenant. "It was the warning in
cipher or code. I didn't think they would neglect to send it to
you."