Upon the "Investigator’s" return to Portsmouth Harbour it was possible to obtain details of what had occurred: The sea wall in front of Southsea Castle was crowded with people who, half-doubting, were yet sufficiently curious to see whether the promise in _The Times_ would be redeemed. They saw the two aero-hydroplanes approach and manoeuvre over the pre-arranged area. They heard the clocks chime the hour of twelve. They waited a few moments longer, nothing happened, so with a derisive cheer they began to disperse. Some remained--mostly those of the leisured class who were not restricted by the midday meal that the British workman holds up as an established institution. Suddenly--it was exactly at eleven minutes past twelve--a column of water leapt vertically upwards at less than four hundred yards from the shore. There was a shrieking sound like the screech of a high velocity projectile, followed by a detonation so powerful that most of the spectators on the sea-front were deaf for days afterwards. The ground trembled, several persons were overthrown; the windows of several houses overlooking the common were broken. Expecting a shower of scraps of metal from the bursting projectile the terror-stricken crowd broke and ran, but curiously enough no one could afterwards be found to report that anything of a solid nature fell to earth. Captain Restronguet’s token was merely an explosive rocket of high power. That same afternoon news came that a German seagoing training-ship, the "Sachsen" was sunk by some unknown means in Kiel Harbour, and another green and white buoy bearing Captain Restronguet’s name, was found floating over the wreck of the sunken vessel. By what manner, incomprehensible beyond the wildest dream of fiction, could this Captain Restronguet be at Portsmouth just after noon and at Kiel, in the Baltic Sea, two hours later? Was his submarine in possession of supernatural powers whereby he could annihilate space and practically conquer time? The theory was no sooner advanced than it was regarded as utterly impossible; the opinion that Captain Restronguet was, after all, not responsible for the outrages at Wilhelmshaven began to gain ground both in Great Britain and Germany. In naval and military circles the importance of the offensive powers of the mysterious submarine were fully commented upon. It was recognized that submarine warfare was more than likely to regain the supremacy that had been wrested from it by aircraft. Here was a submerged vessel, invisible although only in seven fathoms of water, that could project a shell charged with a high explosive vertically to a great height. Although not in the accepted sense of the word an aerial torpedo, the rocket had seriously affected the stability of the two aero-hydroplanes that were at a distance hitherto considered as a safe margin. Had it been an aerial torpedo instead of a rocket the result would have been terrible to contemplate.