They had not yet sighted the enemy behind, nor had any intimation that one was there. For the snapping up of the guard had been done with little noise, the few shouts uttered being inaudible to them amid the continuous splashing and plunging of their own horses. It was only after the pursuing party was well out into the flood, clear of the tree-shadowed shore, that some of the hindmost, chancing to look back, saw what they took to be their rear-guard in the water and riding after them. Saw it with surprise, as the signal for its advance had not been given; no note of bugle sounded. Neither could it be in retreat, driven in. There had been no firing, not a shot; and, by the Prince's orders, there should have been a prolonged fusilade Guard of his, rear or van, retiring from its post without execution of his commands, had better have stayed and delivered itself up to the enemy. Well knowing this, they who first sighted the pursuers, thinking them of their own, were enough astonished to give way to ejaculations. Which ran along the line quick as lightning. "What is it?" demanded he at the head, on hearing them. "The rear-guard, your Highness," answered one away at the back. "They're coming on after us." "Halt!" shouted the Prince, in a voice of thunder, half-wheeling his horse, spurring out to the utmost edge of firm footing, and, with craned neck, looking back land-ward. For a time to see nothing much beyond the tail end of his escort. Only the grey glimmer of water, with here and there the top of a pollard willow. For the capricious clouds had once more muffled the moon. But he heard something; the sound of the wading horses, that made by his own now ceased from their being at a stand. And soon he saw the moving ones; the clouds, by like caprice, having quickly drawn off their screen, letting full moonlight down upon the water. Saw them with alarm; for a dark mass was that in motion, too dark and too large for the score or so of files that had been detached as a guard. "_Gott_, Colonel!" he exclaimed, "there are more men there than we left with Trevor. And why should he be coming on contrary to orders? It cannot be he?" "Very strange if it be, Prince," rejoined Lunsford, the colonel spoken to; "and stranger still if not." "Could a party have slipped past without the guard seeing them?" "Hardly possible, your Highness; unless by some swimming, and a long roundabout way. These seem to come direct from it." The two talked hurriedly, and with dismay upon their faces. For the dark mysterious thing, still drawing nigher and nearer, seemed some unearthly monster--a hydra approaching to destroy them. There was no time for further conjecturing. Friend or enemy, it must be met face to face; and Rupert, commanding the "about," put spur to his horse and started towards the rear of the line.