puzzling over tables of intricate figures, and Mrs.
Baggert was in the kitchen, sighing occasionally as she thought of Tom,
whom she loved almost as a son, high in the air, when two men came up
the walk, from the street, and knocked at the side door. Mrs. Baggert,
who answered the summons, was somewhat surprised to see Chief of Police
Simonson and Constable Higby.

"They probably came to see the airship start," she thought, "but
they're too late."

"Ah, good morning, Mrs. Baggert," greeted the chief. "Is Mr. Swift and
his son about this morning?"

"Mr. Swift is in his library, but Tom is gone."

"He'll be back though, won't he?" asked Constable Higby
quickly--anxiously, Mrs. Baggert thought.

"Oh, yes," she replied. "He and--"

"Just take us to see Mr. Swift," interrupted the chief, with a look of
caution at his aide. "We'll explain matters to him."

Wondering what could be the mission of the two officers, Mrs. Baggert
led them to the library.

"It's queer," she thought, "that they don't ask something about the
airship. I suppose that was what they came for. But maybe it's about
the mysterious men who robbed Mr. Swift."

"Ah, gentlemen, what can I do for you?" asked the inventor, as he rose
to greet the officials.

"Ahem, Mr. Swift. Ahem--er--that is--well, the fact is, Mr. Swift,"
stammered the chief, "we have come upon a very painful errand."

"What's that?" cried Tom's father. "I haven't been robbed again, have
I?'

"There has been a robbery committed," spoke the constable quickly.

"But you are not the victim," interposed the chief.

"I'm glad of that," said Mr. Swift.

"Where is your son, Tom?" asked the head of the Shopton police force,
sharply.

"What do you want with him?" inquired the inventor, struck by some
strange tone in the other's voice.

"Mr. Swift," went on the chief, solemnly, "I said we came upon a very
painful errand. It is painful, as I have known Tom since he was a
little lad. But I must do my duty, no matter how painful it is. I have
a warrant for the arrest of your son, Thomas Swift, and I have come to
serve it. I need not tell you that it is your duty to give him up to
us--the representatives of the law. I call upon you to produce your
son."

Mr. Swift staggered to his feet.

"My son! You have come to arrest my son?" he stammered.

The chief nodded grimly.

"Upon what charge?" faltered the father.

"On a charge of breaking into the Shopton National Bank last night,