Perhaps a hundred yards away in the darkness Frank's keen eyes now made out the forms of many little craft approaching them silently and swiftly. He immediately called Lord Hastings' attention.
"The motorboats," replied the latter quietly. "Things are working out just right."
Behind the motorboat flotilla could be seen forms of larger and mightier ships of war—the torpedo boats which were advancing in the wake of the mosquito fleet to surround the enemy submarines and capture or sink them. They came along close to the shore on either side of the river and the U-16 continued up the river in the exact center.
"When we get by, they'll close in," said Lord Hastings.
But now one of the commanders with the motorboat flotilla could restrain his impatience no longer, and while still some distance from the enemy gave the command to fire.
A single big gun boomed in the darkness and a shell screamed over the U-16 toward the German submarines beyond.
"The fool!" exclaimed Lord Hastings angrily. "Why could he not wait? There is no reason for concealment longer."
Immediately he gave the signal agreed upon with the German admiral, the darkening of the tail light—the signal for the others to submerge—and the U-16 dashed forward faster than before—to reach a place of safety as quickly as possible and to get out of range of the British ships, which, a moment later, opened upon the enemy with every available gun.
Directly opposite the U-16 there was a terrible explosion, a blinding flash, illumining the night like day. A German submarine had launched a torpedo and it had gone home. The foremost British torpedo boat had been destroyed.
But the others rushed on.