"Then see what you can make of that," pointing to the rapidly waving flag. "I shall require corroboration."
"'_Make an attempt to leave the ship tonight; we will be awaiting you,_'" read Gerald.
"That's it," assented Captain Brookes. "They've finished for the present; but I've learnt enough."
DURING dinner there was nothing to indicate that ere morning strange doings were to be enacted on board the _Olive Branch_. Captain Brookes had given strict instructions to those who were in the secret to maintain silence and to abstain from any words that might alarm the traitor.
The meal therefore proceeded as smoothly as usual, though Gerald noticed that Taylor, _alias_ Schneider, was ill at ease, refraining from indulging in conversation, and looking across the table in an absent-minded manner.
When permission was given to smoke the captain excused himself and withdrew.
"Well, Mr. Sinclair?" said he to the officer of the watch.
"I've examined the stern-walk, sir; there is a snatch-block and a coil of rope under the seat."
"Very good; I'll have the lights going in my cabin and the curtains drawn over the scuttles and gallery door. Keep an eye on Taylor without being observed, and when he makes for the stern-walk inform me."
Shortly after midnight word was brought that the scientist had lowered himself on to the stern gallery; and Captain Brookes, Gerald, Stockton, and the officer of the watch crept cautiously aft so that they could hear the traitor's movements.
The night was pitch dark. All the deck lamps were screened, save the navigation lights, which were invisible from the quarter-deck. The _Olive Branch_ was still maintaining a steady ten knots, her wake showing a path of faint phosphorescence till it was interrupted by the hull of the German tramp a cable's length astern.
After a quarter of an hour's vigil the watchers were rewarded by the sound of a sullen splash, and a dark object, outlined in a spray of dim light, veered slowly astern.
"Has he jumped overboard?" whispered Jack Stockton.
"Hist! No, he's slung the life-buoy overboard. There's a line bent on to it."
"You're right," remarked Captain Brookes, as he watched the towed craft through a pair of night-glasses. "They've brought the buoy over the side."