"Koku," went on Tom, in even tones, "just show these gentlemen
to the front door--and lock it after them," he added
significantly, as he turned back into the shop, followed by Ned.

"Yes, Mr. Tom," answered the giant, and then, with his big
hand, and brawny fist, he gently turned the two men toward the
outer door. They were gasping in surprise as they looked at the
giant.

"You'll be sorry for this, Tom Swift!" exclaimed Mr. Turbot.
"You'll regret not having taken our offer. This Period chat is
only a small dealer. We can do better by you. You'll regret--"

"You'll regret coming here again," snapped Tom, as he closed
the door of his shop, leaving Koku to escort the baffled plotters
to their auto. Shortly afterward Tom and Ned heard the car
puffing away.

"Well, they came, just as Mr. Period said they would," spoke
Tom, slowly.

"Yes, and they went away again!" exclaimed Ned with a laugh.
"They had their trip for nothing. Say, did you see how they
stared at Koku?"

"Yes, he's a helper worth having, in cases like these."

Tom wrote a full account of what had happened and sent it to
Mr. Period. He received in reply a few words, thanking him for