Tom drifted in within a few feet of the former site of the retaining wall. The "Morton" moved slowly by, Tom, by the aid of the searchlight, noting the extent of the disaster.

"Get back aft, Evarts," ordered the young engineer, turning and beholding the late foreman. "We don't want you here."

For a moment or two it looked as though Evarts would refuse. Then, with a growl, he rose and picked his way aft. By this time the other men who had been in his gang were awake. They regarded their former foreman with no great display of sympathy.

"I'll confess I'm mystified," muttered Tom, watching the scene of the latest explosion for some minutes after the engine had been stopped. "When daylight comes and we can use the divers we ought to know a bit more about how such a big blast is worked in the dead of night when the scoundrels ought to make noise enough to be heard. It must have been a series of connected blasts, all touched off at the same moment, Mr. Renshaw, but even such a series is by no means easy to lay. And then the blasts have to be drilled for, and then tamped."

"As you say, sir," replied the superintendent, "a much clearer idea can be formed when we have daylight and the divers."

Tom held his watch to one side of the searchlight.

"Nearly two hours yet until daylight, Mr. Renshaw," he announced. "And, of course, it will be two or three hours after daylight before we can get the divers at work. A fearful length of time to wait!"

"You'd better go back to the shore, sir," urged the superintendent.

"Not while this boat needs to be run," objected Reade. "For the rest of the night I want a man here whom I can trust."

"Will you trust me with the boat?" proposed the superintendent.