“Tom, I’ll talk to the president’s special science adviser at once,” the man promised.  “I’ll try to set up a meeting for ten o’clock tomorrow morning at Enterprises.”

Feeling relieved, Tom left the plant with Bud.  The two boys drove off to attend church with Mrs. Swift and Sandy.  Then, after the Sunday midday meal, Tom returned to his laboratory to work on ideas for a shock-wave deflector.

Bud and Sandy, meanwhile, drove to the Shopton Yacht Club to inspect the damage to the Sunspot.  Tom had arranged with a salvage crew to tow the disabled ketch back to its slip.

Monday morning, a sleek Air Force jet transport touched down at Swift Enterprises.  Aboard were a select group of top government scientists.  Tom and Bud greeted them as they disembarked on the runway, then drove them to a conference room in the Enterprises main building.

“I’d say your theory is right, Tom, about the quakes being produced by artificial shock waves,” said Bernt Ahlgren, a tall, hawk-faced man with a shock of red hair.  He was a member of the Defense Department’s Advanced Research Projects Agency.  “But how do we stop them?”

“I believe they can be damped out by opposing waves,” Tom replied.  “This is assuming that I can design the right sort of equipment to do the job—­and also that we can set up a warning system to alert us of the enemy shock waves in time.”  The young inventor sketched out the sort of shock-wave deflector which he had in mind.  The government experts were very much impressed.  In the session that followed, the visiting scientists contributed many tips and suggestions.  Tom noted them down gratefully.

After a thorough discussion, it was agreed that the Defense Department would set up detectors at fifty check points around the country.  Tom would choose the exact spots.  Detection data from the check points would be fed to an electronic computer.  The computer would establish the pattern, if any, of incoming enemy shock waves.

Dr. Gregg Miles, a seismologist from the Bureau of Mines, agreed to take on the job of setting up the check points.

“Thanks for your prompt co-operation,” Tom said, smiling gratefully as the meeting broke up.

“We should thank you, Tom, for coming up with a plan to cope with this fiendish threat,” Ahlgren replied.  The others heartily agreed.

Shortly after lunch, Tom was hard at work in his laboratory when the telephone rang.  It was Chief Slater at Shopton police headquarters.

“You’d better get over here fast, Tom,” Slater said.  “Samson Narko is ready to talk!”

Tom needed no urging.  “Right, Chief!”

As he drove into Shopton, Tom wondered what the Brungarian agent would reveal.  Was it possible that he might tip off the whole secret behind the destructive man-made earthquakes?

Chief Slater was waiting in his office.  “Narko showed signs of cracking this morning,” Slater told Tom, “so I notified the Central Intelligence Agency.  They’re flying a man up here—­in fact he should be here by now.  Narko won’t talk till he arrives.”