“What’s that!” exclaimed Mr. Perry, seizing the youth by the arms.  “You say you got that kind of message from those boys?”

“Sure I did,” the boy replied; “and they want you to hurry back.”

“What kind of men are they—­rough characters, bad men?”

“That’s what I understood him to mean.”

“Come on, Mr. Baker, Bob; we must hustle along.  Thank you, my boy; you’ll hear from me again.”

“I’ll hurry back and tell the boys I found you and you’re on your way,” shouted Max as he ran down the street toward home.

Mr. Perry led the way toward the dock at a rapid pace.  Presently they found themselves in front of a hardware store, and the owner of the Catwhisker stopped and said: 

“I’m going in here a minute.”

He entered, and Mr. Baker and Cub followed, wondering a little as to the motive of the boy’s father.  But they were not long left in doubt.

“Have you any fire-arms on sale here?” Mr. Perry asked, addressing the proprietor.

“Small or large?” the latter inquired.

“Small.”

“Right this way.”

He stepped behind a show case in which was a display of automatics and revolvers.  Mr. Perry selected one of the former and a box of cartridges and took out his pocketbook to pay for them.

“I believe I’ll take one, too,” interposed Mr. Baker, also producing a purse.

The storekeeper looked somewhat curiously at the two men.

“I’m supposed to exercise care and judgment in selling these weapons,” he remarked slowly.

“Of course, of course,” returned Mr. Perry.  “The situation is this:  We belong to a yacht on the river and have run up against some bad characters.  I am the owner of the yacht and have decided that we need protection.”

“Sure, sure, that’s perfectly satisfactory,” said the hardware man.  “You can buy out my whole arsenal on that explanation.”

“We won’t need it,” Mr. Perry smiled.  “These two guns are enough.”

The purchase completed, the two men and the boy left the store and hastened on toward the municipal docks.

Meanwhile Max arrived at his home and went direct to his radio room.  There the first thing he did was to don his phones, and the result was instantly startling.

He had left the instrument tuned to the Friday Island wave length and the aerial switch in receiving position.

“S O S, S O S, S O S,” crashed into his ears in rapid, energetic, excited succession, it seemed to his susceptible imagination.

Quickly he threw over the switch, and called for an explanation.  It came as follows: 

“Those men have seized my friend, and now are coming after me.  S O S, S O—­”

That was all—­not another dot or dash.  Desperately Max appealed for further details, but it was like calling for life in a cemetery.  The ether was dead, so far as Friday Island was concerned.