He broke off suddenly, as Captain Petersen called out:

“The Nereid! There she is!”

Following with their eyes the bright segment cut into the murky depths by his flashlight, they saw the familiar outlines of their craft; and close beside her lay the U-boat.

A feverish activity seemed to be going on between the two submarines.

“They’re changing cargo!” cried Larry. “Quick! We’ve got them now!”

But the progress they were able to make, hampered by their heavy suits, was maddeningly slow. Their searchlights, moreover, betrayed their approach. Before they could reach the scene, most of the sailors had abandoned their task and piled into the U-boat.

Arms swinging wildly, Von Ullrich stood beside it, trying to rally then. Refusing to risk combat, however, since they were unable to use their deadly hand-grenades under water, they continued clambering up the sides of their submersible and shoving down through its conning-tower hatch.

Now a figure in a familiar pressure-suit broke away and started toward the advancing party.

It was Diane!