s the boat reached the bank of Bush
River. Before him stretched a dismal swamp, interspersed with
occasional bits of higher ground. He looked back over the river for a
moment, taking his bearings with great care. A luminous lensatic
compass gave him the orientation of the points he had chosen for
markers.

"Are you sure we are at the right place?" he asked in an undertone.

"Sure as shootin', Mister," replied the boatman. "It's the only place
of its kind in five miles. The rock you're hunting for is about a
hundred rods due east."

"It looks right," said Carnes. "Come on, men."

Operatives Haggerty and Dillon scrambled out of the boat and stood by
his side.

"Follow me," said Carnes in a whisper.

Both detectives nodded silently. They drew their pistols and fell in
behind their leader. Keeping his direction with the aid of his
compass, Carnes led the way forward, counting his steps. At five
hundred he paused.

"It should be right here," he whispered.

Haggerty pointed in silence. In the starlight, a large rock loomed up
a few yards away. With an exclamation of satisfaction, Carnes led the
way to it.

"Dig on the south side," he whispered, "and hurry! The damned thing is
due to go off in less than twenty minutes. Unless we can find and cut
the wire before then, the doctor is a gone gosling."

The two detectives drew intrenching shovels from their pockets and dug
feverishly. For five minutes they labored. Dillon gave an exclamation.

"Here it is, Chief!" he said.

Carnes bent down and ventured a short flash from a carefully guarded
light. The detective's shovel had unearthed a powerful cable running
through the earth.

"Get something to cut on!" cried Carnes.

Haggerty lifted a rock which they had unearthed and thrown to one
side. Carnes raised the cable and laid it on the rock.

"Now for your ax, Dillon!" he exclaimed.

He turned on his flashlight. Dillon raised a hand-ax and took careful
aim. Sparks flew as the ax fell on the rock, severing the cable
cleanly. Carnes rose to his feet.

"The doctor's safe!" he cried.

* * * * *

He started at a run toward the north. He had gone only a few feet when
a beam of light flashed across the marsh, picking him out of the
darkness. He paused in amazement.

A flash of orange light stabbed the darkness and a heavy pistol bullet
sang past his head. The detective raised his weapon to reply, but
three more flashes from the darkn