you," grunted Mr. Bascomb. "I don't exactly
like the idea of staying here alone in such troublesome times."

Harry walked beside Mr. Bascomb, while Tom led the way with the treasurer.
Mr. Renshaw brought up the rear.

As the party came in sight of the beach and glanced out seaward, they saw
many a little, dancing light out on the retaining wall. Each light showed
where a workman patrolled under the orders of Foreman Corbett. The latter
was aboard the motor boat, "Morton," which ran up and down near the wall,
throwing the searchlight over the scene.

"Reade," remarked Mr. Prenter, "I don't see that the enemy have any chance
to-night to run in and work harm to our property."

Hardly had the treasurer spoken when Tom, looking out seaward, saw a
sudden, bright flash of light upward. There was a brief pause---then the
sullen boom of an explosion reached their ears.

"Mystery of all mysteries!" choked Tom Reade. "There goes another section
of the wall---blown up under our very eyes!"

CHAPTER XI

A MESSAGE FROM A COWARD

"Now Reade," began President Bascomb, in a shaking voice, "what can you
say---"

Tom didn't wait to inform him. The young chief engineer was darting out on
the wall as fast as he could go.

Already the "Morton" had turned, and was chugging back to the scene of this
latest outrage, the searchlight flashing back and forth, in the vain effort
to detect any small craft stealing away from the vicinity.

"I---I can't race on a narrow runway like that," faltered Mr. Bascomb,
halting at the beginning of the narrow wall. "I---I'll wait here, Mr.
Renshaw, will you keep me company?"

"If you so direct, sir," replied the superintendent. "For that matter,
what Reade and Hazelton can't find out, out yonder, will probably never be
discovered."

"Do you share Mr. Prenter's infatuation for those two young men?" asked
the president of the Melliston Company.

"I can't say about that, sir," Renshaw replied, with a puzzled air. "But
this much I know---I never worked with two more capable men of any age.
They always know what to do, and they never lose their heads."

Mr. Bascomb compressed his lips tightly.

In the meantime Tom, Harry and Treasurer Prenter covered nearly a quarter
of a mile along the retaining wall when the motor boat, putting about,
picked them up with the searchlight.

Toot! toot! sounded the boat's pneumatic whistle.

"Foreman Corbett is signaling to us to wait and he'll p