cause an earthquake ought to be strung up like a hoss thief!"

"I agree, Chow," Tom said. "But how do we find out for sure?"

After closing time at the plant, Bud drove home with Tom. Both Mrs.
Swift and Sandy were upset as the boys discussed the situation.

"Tom, if this was deliberate," Mrs. Swift pointed out, "Enterprises may
be next on the enemy's list!"

Tom did his best to allay his mother's fears, but inwardly he himself
felt apprehensive. Any large-scale sabotage plot would be almost certain
to include Swift Enterprises, America's most daring and advanced
research center.

When his mother went upstairs to her room, Tom suggested to Bud that
they drive to the nearby State Police post. Here he confided his fears
to Captain Rock, an old friend of the Swifts.

"You have some request in mind?" Captain Rock inquired.

"How about making a search for any signs of suspicious digging or
underground activity in the vicinity of Shopton?" Tom said. "There would
have to be an excavation of some sort in order to set off an underground
blast."

Captain Rock mulled over Tom's suggestion. "Sounds like a big job, but
I'm afraid you're right, Tom. We can't risk a similar disaster here."

"We'd better move fast, too," Bud put in. "Those two quakes so far came