The air was calm and clear and the sea smooth. Half a dozen of the most powerful telescopes and marine glasses were engaged by as many expert watchers in sweeping the sea, while at the end of the pier a naval gun was charged and a crew of experienced marksmen were at the breech ready to train it on the instant if the Germans' periscopes should be sighted.
Mark Redisham was the first to discover a ripple on the water some three miles away, but it was one of the officers who determined that the ripple was caused by the movement of a half-submerged submarine. It was apparently making towards Alderwick Roads, where half a dozen patrol trawlers lay at anchor.
The light was gradually fading, but the moving target was still visible. The gun was laid. For months back, at intervals, it had been brought into practice upon a mark less easily seen than the one upon which it was pointed at this moment, and the gunner who now controlled its aim had never been known to fail.
The lever was pressed. The shell shrieked forth. Then there was a terrific explosion which shook the windows of the town as the submarine was struck and sent to its doom.
An electric launch was sent out to pick up possible survivors, but all that could be seen was a slimy film of oil on the water's surface.
From the pier as the boat went out, the periscopes of the second submarine were sighted, but before the gun could be trained it had disappeared.
CHAPTER XXXII.
U50'S WORST CRIME.
"This second submarine was the U50.
"It's that naval gun on Haddisport pier that I warned you of," said Max Hilliger, as the vessel submerged and her electric motors were turned on. "We ought not to have come in so close. I believe those mine-sweepers in the Roads must have discovered us. Most of them are fitted with wireless masts. No, it's no use trying to rescue our friends. They couldn't have escaped after an explosion like that. We had better remain submerged and get away from the coast as quickly as we can."