"I wish I had even an idea," Tom sighed. "Corbett, I wish you would hurry over to Blixton and rout out the police. I've an idea that Sambo may have a hiding place in the town. Nicolas, too, may have been taken that way.

I'll sit down and write out a good description of the rascal."

This Reade did, handing the paper to the foreman.

"Who'll take charge here? Corbett asked.

"I will, until you get back, but hurry."

As soon as the foreman had gone Tom stepped into the motor boat, taking the wheel.

"Tune up the engine, Conlon," Reade directed the engine tender. "I'm going to take a run around to the west side of the wall. I'm going to try to find the tubes of high explosive that I'm satisfied were planted in the wall."

"That's a fine job for a dark night, sir," grumbled Conlon. "Suppose we run into the bombs, and they prove to be contact exploders, too?"

"That's one of the risks of the business," Tom retorted grimly.

Before the motor boat had gone far Tom called one of the men aboard to take the wheel. Then the young chief engineer began to experiment with the searchlight.

"What's the idea, sir?" asked Conlon, looking on.

"I want to depress the light, so that we can use it to look down into the water."

"And try to find the bombs?"

"Exactly," Reade nodded.

"Lucky if we don't find the bombs with the keel of the boat," observed Conlon.

Tom succeeded in rigging the light so that he could use it. By the time that the boat was around at the west side of the retaining wall Tom ordered the boat in close alongside. Then, with the depressed searchlight he discovered that he could see the sides of the wall to a depth of some eight feet under the surface.

"That may be enough for our needs," Reade murmured. "Now, run the boat along, slowly and close. I want to scan every bit of the wall."

Less than five minutes later Tom Reade, one hand controlling the searchlight and peering steadily into the water, sang out:

"Stop! Back her---slowly. There, come back five feet. So! Hold her steady!"

As the engine stopped Conlon stepped forward, kneeling by Reade's side.

"There are the bombs, man!" cried Tom exultantly. "See them---the two upper ones?"

"I see something that gleams," admitted Conlon.

"Well, we'll have them up and aboard in a hurry. Then you'll see just what they are."

"You're not going to try to raise the things with the boathook, are you?"

queried the engine tender, a look of alarm in his eyes.

"That might be risky," admitted Reade. "I'll go over the side after them and bring them up.

"Don't, Mr. Reade!" urged Conlon with a shiver. "That'll be worse still.

You're likely to blow yourself into the next world!"

"I think not---hope not, anyway," answered Tom steadily. "Have you a pair of pliers in your tool box that'll cut small wires?"

"Yes," replied Conlon.

"Get them for me."

Reade removed his coat, shoes and socks, then took the pliers.

"Let one of the men jump ash.o.r.e with the boathook and hold the boat steady," was Reade's next direction.

This being done, Reade deflected the searchlight for one more look into the water. Then, the pliers in his right hand, he mounted to the rail of the boat.

"Be careful, sir---do," begged Conlon. "What I'm afraid of is that the bombs are contact exploders."

"It's likely," nodded Reade. "I'll be as careful as I can."

Tom did not dive; the distance was too short. Instead, he let himself down into the water slowly. Then his head vanished beneath the surface of the water.

"Whew! The nerve of that young fellow!", thought Conlon with shuddering admiration.

"Ob co'se Ma.s.sa Reade done got nerve," nodded the negro at the wheel.

"Dat's one reason why, Misto Conlon, Ma.s.sa Reade is boss."

"There are other reasons why he's boss," grunted the engine tender. "Mr.

Reade has nerve, but he also has brains in his head. Any man with brains and the sense to use 'em goes to the top, while I stay down a good deal lower, and you, Rastus, are still lower."

"Ah reckon Ah got a two-bit hat on top o' only two cents' wo'th o' brains, Misto Conlon," grinned the darkey.

Conlon was an Irishman, and naturally, therefore, no coward. Yet with the possibility that Tom would run afoul of a contact-exploding bomb and send them all skyward, the engine tender waited at the rail with drawn breath.

Finally, there was a ripple on the water. Then Tom's head appeared; next his shoulders.

"Conlon!"

"Here, sir."

"Here is one of the bombs. Handle it carefully."

"Trust me, sir."

Conlon drew the metal tube, with a piece of wire pendant from it, as carefully as though it had been a royal baby and heir to a throne. Into the boat the engine tender lifted the thing, and laid it carefully in a locker. By the time that Conlon was back at the rail Reade had gone below again.

"Down dere, aftah mo' death!" grinned the darkey. A colored man can usually be brave when serving under a white leader in whom he has full confidence.

Presently Tom came up with another metal tube, like the first.

"I'll hang on and get my breath," Tom informed the men in the boat, as he rested one hand on the rail. "The other two bombs are about three feet lower, and it's going to be hard to work at the lower depth."