"Well, almost. It can be made ready in a few hours. You see, I have been delayed. There was a fire in the plant."
"A fire!" exclaimed the officer in surprise. "How was that? We heard nothing of it in Washington."
"No, I kept it rather quiet," Tom explained. "We had reason to suspect that it was a fire purposely set, in a shed where I kept a quantity of explosives."
"Ha!" exclaimed Lieutenant Marbury. "This fits in with what I have heard. And did you not receive warning?" he asked Tom.
"Warning? No. Of what?"
"Of foreign spies!" was the unexpected answer. "I am sorry. Some of our Secret Service men unearthed something of a plot against you, and I presumed you had been told to watch out. If you had, the fire might not have occurred. There must have been some error in Washington. But let me tell you now, Tom Swift—be on your guard!"
CHAPTER VIII
A SUSPECTED PLOT
The officer's words were so filled with meaning that Tom started. Ned Newton, too, showed the effect he felt.