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 only a day apart!”

Rock picked up the telephone and barked out orders.  Within half an hour, several carloads of troopers were covering the outlying roads that converged on Shopton.  Firemen and Chief Slater’s town police force were also pressed into action.  They would search every cellar in town for signs of recent digging.

Bud rode in one police car and Tom in another as a house-to-house search was conducted along the highway that ran past Enterprises.

At one weather-beaten house, where Bud stopped with a state trooper, an old man came to the door.

“What you fellers prowlin’ around for?” he asked.

“Bomb emergency,” the trooper said laconically.  “We have orders to search every house cellar for underground openings.”

Grumbling, the old man let them enter.  He followed them down a rickety stairway.  A moment later Bud stumbled and gave a yell.  The trooper swung around just in time to see Bud drop from view!

CHAPTER V

SECRET CACHE

As the trooper’s flashlight stabbed through the cellar gloom at the spot where Bud had disappeared, there came a loud splash!  The light showed a round hole in the floor, rimmed by a low circle of brickwork.

“What’s that hole?” the trooper snapped at the owner.

“What does it look like?” the elderly man snapped back.  “It’s an old well.”

“A well!” the trooper exclaimed as he rushed to the spot.  “And not even covered?  What’re you trying to do—­kill people?”

The old man sniffed.  “Used to be covered, but the lid’s gone.  Didn’t expect to have a bunch of nosy fellers pokin’ around down here!”

The state trooper muttered angrily under his breath as he shone his flashlight into the well-shaft.  Bud was splashing around below, soaked and chagrined by his accident.

“Give me a hand!” he called up.

The trooper reached down, but was barely able to touch Bud’s finger tips.  To make matters worse, the sides of the well were slippery with moss.

“Get a rope,” the trooper ordered the old man.

“Ain’t got one.”

The policeman reddened and stood up to his full six-foot-two.  “Look, mister—­what’s your name?”

The elderly man shrank back, as if suspecting that the trooper’s patience might have been tried too far.  “Ben Smith,” he mumbled.

“Okay, Mr. Smith, you get a rope or something else to pull this boy out.  And fast!”

Ben Smith gulped on his chewing tobacco and hurried off.  A minute or so later he returned with a length of clothesline.  The trooper lowered it into the well and Bud was soon climbing out, looking like a drenched rat.