“You have an urgent call from Washington,” the operator informed him.  “Just a moment, please.”

Bernt Ahlgren was calling from the Pentagon.  The defense expert’s voice was strained.

“Tom, there’s just been another attempt to cause an earthquake here in Washington!”

Tom gasped.  “What happened?”

“It failed, thanks to you.  But Intelligence believes an attempt will be made on New York City very soon.  We need your help to stop it.  How near completion are the other shock deflectors?”

Before Tom could answer, he heard excited voices at the other end of the line.  Then Ahlgren broke in again abruptly.

“A news flash, Tom!  The Walling range-finder plant has been demolished by an earthquake!”

CHAPTER XIV

AIR-BORNE HIJACKERS

Mr. Swift, hearing Tom’s dismayed reaction, rushed to the telephone.

“What’s wrong, son?”

Tom clamped his hand over the mouthpiece and quickly gave his father the news of the destroyed range-finder plant.  Then he spoke into the telephone.

“Bernt, we must prevent another disaster!  Let me check with our construction company on the Quakelizors and I’ll call you right back!”

“Right, Tom,” Ahlgren agreed.

Both Tom and Mr. Swift were shocked by this latest blow of their enemies.  Tom called Ned Newton at the Swift Construction Company at once and told him the news.

“How soon will the Quakelizors be ready, Uncle Ned?”

“They’re finished, Tom.  We’re running a final inspection on them right now.  We can have them ready to ship out by one o’clock.”

Tom relayed word to the Pentagon.  Bernt Ahlgren was greatly relieved.  “By the way,” Tom went on, “what about the sites?  Have they been chosen yet?”

“Only tentatively,” Ahlgren replied.  “We wanted to get your opinion first.”

One of the deflectors, Ahlgren felt, should be based in position to guard the New York and New England area, in view of Intelligence warnings about a probable attack on New York City.  Another, in the Cumberland plateau region of Kentucky, could damp out shock waves threatening either the heavily industrialized Great Lakes area or any southern city.

As to the other three Quakelizors, Ahlgren suggested that one be installed on the West Coast, one in the Black Hills of South Dakota, and the third on the Atlantic island of San Rosario.  This would protect both Latin-American allies and Caribbean defense bases of the United States.

Before deciding, Tom asked that Dr. Miles at the Bureau of Mines be circuited into the telephone conversation.  Mr. Swift, too, joined in on another line.  The four scientists discussed the problem and referred to geologic maps.  Finally the exact sites were agreed upon.

“Dad, I’m going to deliver and install one of those Quakelizors myself,” Tom declared, after the telephone conference ended.  “Judging from that phone impostor last night, there’s no telling what sort of trick our enemies may try next!”