Huckleberry was filled with admiration of Tom's facility in writing, and the sublimity of his language. He at once took a pin from his lappel and was going. to prick his flesh, but Tom said:
" Hold on ! Don't do that. A pin's brass. It might have verdigrease on it."
" What's verdigrease ? "
"It's p'ison. That's what it is. You just swaller some of it once—you'll see."
So Tom unwound the thread from one of his needles, and each boy pricked the ball of his thumb and squeezed out a drop of blood. In time, after many squeezes, Tom managed to sign his initials, using the ball of his little finger for a pen. Then he showed Huckleberry how to make an H and an F, and the oath was complete. They buried the shingle close to the wall, with some dismal ceremonies and incantations, and the fetters that bound their tongues were considered to be locked and the key thrown away.
A figure crept stealthily through a break in the other end of the ruined building, now, but they did not notice it.
"Tom," whispered Huckleberry, "does this keep us from ever telling—always} "
" Of course it does. It don't make any difference what happens, we got to keep mum. We'd drop down dead—don't you know that? "
" Yes, I reckon that's so."
They continued to whisper for some little time. Presently a dog set up a long, lugubrious howl just outside—within ten feet of them. The boys clasped each other suddenly, in an agony of fright.
" Which of us does he mean? " gasped Huckleberry.
" I dono—peep through the crack. Quick ! "
" I can't—I can't do it, Huck! "
"Please, Tom. There 'tis again ! "
"O, lordy, I'm thankful!" whispered Tom. "I know his voice. It's Bull Harbison." *
* If Mr. Harbison had owned a slave named Bull, Tom would have spoken of him as " Harbison's Bull," but a son or a dog of that name was " Bull Harbison."