nly the whole scene seemed to explode. Plant buildings collapsed
like toy houses built of cards, while at the same time huge rocks and
trees were uprooted as a yawning crack opened in the ground below.

The three watchers in Tom's office stared in horrified dismay. But a
moment later the picture on the TV screen became jerky and distorted,
then faded out completely.

After a brief interval, a studio announcer came on. "The relay
transmitter must have been knocked out by the quake. We return you now
to our regularly scheduled program, but will keep you informed as
bulletins come in."

"Great balls o' fire!" Chow gulped as Tom turned off the set. "I sure
hope all o' those poor folks in cars got away safe!"

Tom rushed to a wall shelf and pulled out a book on geology. He leafed
quickly to a section dealing with known earthquake faults and the
distribution of quakes. When he looked up at the others, his face was
grim.

"What's wrong, skipper?" Bud asked tensely.

"That quake," Tom replied, "wasn't in a patterned zone any more than the
Faber one was!"

Chow's jaw dropped open in a comic look of dismay. "You mean this here
ole earth we live on is gettin' all busted up an' twisted around
inside?"

"I wish I knew, Chow!" Tom paced worriedly about the office. "It just
seems queer to me that both of those quakes should have destroyed vital
defense factories!"

On a sudden impulse, Tom snatched up the telephone. His two companions
listened as he put through a call to the FBI in Washington. Within
moments, a friend at the Bureau, Wes Norris, came on the line.

"Look, Wes," Tom said, "is there any chance this quake that just
happened at Medfield and the earlier one at Faber Electronics might have
been caused by underground H-bomb blasts?"

"As a matter of fact, we're checking on that very possibility," Norris
replied. "In other words, sabotage. Things are pretty hot around here
since that news on Medfield came in, so I can't talk much right now,
Tom. But I can tell you this," Wes concluded, "we _are_ investigating,
and I do mean thoroughly!"

Bud and Chow were shocked when Tom reported his conversation with the
FBI agent.

"Brand my rattlesnake stew!" Chow exploded. "Any ornery varmint that'd
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