"I'm quite all right," she declared. "I am enjoying it. How much farther is it, do you think?"
It was Rollo's turn to shake his head. He did not know, and he was too candid to pretend that he did.
"We ought to be meeting shipping in and out of the Thames estuary shortly," he said. "I suppose our merchant vessels sail as freely as they did before the war? Hello! There's something coming up astern."
He pointed to a faint blurr of smoke about three miles away and dead in the wake of the motor-boat.
"Something fairly fast to be able to overtake us," remarked Thelma. "Is there a telescope on board?"
Again he entered the cabin. Kenneth was still sound asleep. Yvonne was seated on the opposite bunk, watching him as zealously as a vigilant sentry.
"What are you looking for, Rollo?" she whispered.
She arose and, steadying herself by means of the cabin table, made her way to the for'ard bulkhead. Drawing back a curtain, she took down the required article from a rack.
"It is a nurse's duty to become quickly acquainted with her surroundings," she said with a smile, as she handed Rollo the telescope.
The lad returned to the cockpit. Standing with his back against the after bulkhead of the cabin he raised the telescope. It was some time, owing to the motion of the boat, before he could get the instrument to bear.
"Why?" asked Thelma. "Tell me: is there anything wrong? I will not be frightened."
"There is, I fear," he answered. "Unless I am very much mistaken, yonder craft is a German torpedo-boat, and she is standing in pursuit of us."
Everest opened his eyes listlessly. Aroused in the midst of the sleep of utter exhaustion, he did not at once realize his surroundings.
"What's up?" he asked drowsily, with a suspicion of resentment in his voice.
"Come out into the cockpit," said Rollo. "I want you to see if we are on the right course. We passed the tramp steamer some time ago."
"Then why didn't you call me?" demanded Kenneth, displaying considerable alacrity, and making a dash for the cabin door.
"Stay here a little longer, Yvonne," said Rollo to the Belgian girl as she began to follow her patient. The lad's chief anxiety was to keep her in ignorance of the new danger that threatened them.
"Right as rain," announced Kenneth, glancing at the compass.