An officer's head popped up through the manhole of the conning tower, then almost as quickly was withdrawn.
As the "Grigsby," obeying her engines, leaped forward, the men behind both forward guns stood ready to fire at the word.
For the submarine crew to bring either gun into place would be the signal for the destroyer to open fire at a range constantly decreasing. Nor could the enemy craft employ her torpedo tubes without turning, which would have been instant signal for Darrin to order his gunners to fire on the submarine.
Through the manhole of the enemy craft leaped a signalman, flags in hand. Using the international code he wigwagged rapidly this message:
"We will make a grace of necessity and surrender."
"That doesn't necessarily mean that they do surrender," Dave 'phoned to the officer in charge of the forward gun division. "If the enemy makes a move to bring a gun into view, or to swing so that a torpedo tube could be used, fire without order and fire to sink!"
The German commander evidently understood that this would be the course of the Yankees, for as the "Grigsby" bore down upon the submarine not a threatening move was visible.
Instead, the Hun crew, unarmed so far as the watchers on the destroyer could see, emerged from the conning tower and moved well up forward.
"Prepare to lower two boats," Dave called, and added instructions for a large crew for each launch. As the "Grigsby" came about and lay to, the launches were lowered. In the bow of each small craft was mounted a machine gun ready for instant action. The double prize crew was permitted to board the submarine without sign of opposition. At the command, German seamen began to file past two petty officers, submitting to search for hidden weapons, then passing on into the launches alongside.
Last of all four officers came through the manhole, preparatory to enduring the same search. When all the prisoners had been taken aboard, the launches started back to the "Grigsby."