recent adventures were
already shorn of their terrors, and only thought of as something
unpleasant, to be forgotten as quickly as possible. Therefore they did
not speak of them as they talked together in low tones, but only of the
present and the future.

"I think it's awful good of you and your mother to take Bill Tooley into
your own house and nurse him," said Paul.

"Oh no," laughed Derrick, "it isn't so very good. Revenge is what we are
after, and that is one way of getting it."

Hearing Bill Tooley's name mentioned between the boys, one of the miners
who rode in the car with them had leaned forward to learn what they were
saying. At Derrick's last remark this man started back and gazed at him
curiously.

"He's got the very stuff in him to make a Mollie of," he thought. "To
think he's so sly. He's got the fellow he hates into his own house,
pretending that he wants to nurse him, and now he's going to take out
his revenge on him. Perhaps he's going to poison him, or fix pins in the
bed so they'll stick him. Anyway, I'll have to give Monk the hint of
what he's up to." Then, admiringly, and half aloud, he muttered, still
looking at Derrick, "The young villain!"

From the foot of the slope Derrick set off for the stable to get Harry
Mule, while Paul waited for the making up of a train of empty cars, in
which he was to ride to the junction near the blacksmith's shop. There
Derrick was to meet him, take him to his post of duty, and tell him
about opening and closing the door, and tending the switch of which he
was to have charge.

In spite of the fact that he and Derrick had been friends but a single
day, Harry Mule appeared to recognize his young driver, and gave him a
cordial greeting as he entered the stable. At least he threw up his head
and uttered a tremendous bray, which went "Haw! he-haw, he-haw, he-haw!"
and sounded so absurdly like a laugh that Derrick laughed from sympathy
until the tears ran down his cheeks. The mule gazed at him with a look
of wonder in his big eyes, and stood so meek and quiet while his harness
was being put on that Derrick thought perhaps his feelings had been
hurt. To soothe them he talked to him, and told him that Paul had come
down into the mine to work.

As they left the stable, and Derrick stopped to fasten the door, Harry
started in the opposite direction from that in which he should have
gone, and ran down the gangway, kicking up his heels and braying, as
though he were a f