"It's nothing much, dad," said the youth, as quietly as he could, for he
realized that to excite his father might have a bad effect on the
invalid.

"Then why are you in such a hurry? Why have you that revolver? I know
there is something wrong, Tom. I am going to help you!"

In his father's present weakened state Tom desired this least of all, so
he said:

"Now, never mind, dad. I thought I heard a noise out in the yard, and
I'm not going to take any chances. So I roused Mr. Jackson, and I'm
going down to see what it is. Perhaps it may only be Eradicate's mule,
Boomerang, kicking around, or it may be Rad himself, or some one after
his chickens. Don't worry. Mr. Jackson and I can attend to it. You go
back to bed, father."

Tom spoke with such assurance that Mr. Swift believed him, and retired
to his room, just as the engineer, partly dressed, came hurrying out in
response to Tom's summons. He had his rifle, and, bad the invalid
inventor seen that, he surely would have worried more.

"Come on!" whispered Tom. "Don't make any noise. I don't want to excite
my father."

"What was it?" asked the engineer.

"I don't know. Burglar alarm went off, that's all I can say until we get
to the shed."