We were just starting to cross the bridge.

One of the men broke away and crawled toward the plunger box.  Our car was now in the middle of the bridge.

Over and over rolled the men, the dog doing his best to help his master.  The man who had broken away reached toward the plunger.

With a shout he pushed it down.

. . . . . . .

Our car had just cleared the bridge when we were startled by a terrific roar behind us.  It was as though a thousand tires had blown out at once.  Elaine shut off the engine automatically and we looked back.

The whole bridge had been blown up.  A second before we had been in the middle of it.

As the explosion came, the men who had been struggling in the thicket, paused, startled, and stared out.  At that instant the old farmer saw his chance.  It was all over and he bolted, calling the dog.

Along the road to the bridge he ran, two of the men after him.

“Come back,” growled the leader.  “Let him go.  Do you want us all to get caught?”

As the farmer ran up to the bridge, he saw it in ruins.  But down the road he could see Elaine and myself, sitting in the car, staring back at the peril which we had so narrowly escaped.  His face lighted up in as great joy as a few moments before it had showed despair.

“What can that have been?” asked Elaine, starting to get out of the car.  “What caused it?”

“I don’t know,” I returned, taking her arm firmly.  “But enough has happened to-day.  If it was intended for us, we’d better not stop.  Some one might take a shot at us.  Come.  We have the car.  We can get out before any one does anything more.  Let’s do it.  Things are going on about us of which we know nothing.  The safest thing is to get away.”

Elaine looked at the bridge in ruins and shuddered.  It was the closest we could have been to death and have escaped.  Then she turned to the wheel quickly and the little car fairly jumped ahead.

“Oh, if Craig were only here,” she murmured.  “He would know what to do.”

As we disappeared over the crest of the next hill, safe, the old farmer and his dog looked hard at us.

The silence after the explosion was ominous.

He glanced about.  No one was pursuing him.  That seemed ominous, too.  But if they did pursue he was prepared to elude them.  They must never recognize the old farmer.

As he turned, he deliberately pulled off his beard, then plunged again into the woods and was lost.

CHAPTER IX

THE SUBMARINE HARBOR

It was not long after the almost miraculous escape of Elaine and myself from the blowing up of the bridge on the shore road that Del Mar returned from his mysterious mission which had, apparently, taken him actually down to the bottom of the sea.