The Russian shook his hand heartily; then turned to the work of looking after the dead and wounded. Lord Hastings and Jack turned their eyes toward the German cruiser, which was slowly sinking. Hundreds of German sailors were in the sea, clinging to such pieces of débris as came to hand. Immediately the Russians launched life boats and set about the work of rescue; and all who were in the water were saved, the German commander among them. Then the German cruiser sank; and as she disappeared from sight, at a point not half a mile distant, another form appeared upon the surface. It was the D-16. The Russian commander, who stood near at that moment, turned to Lord Hastings. "I shall be pleased," he said, "to have you sent back aboard your ship immediately. Or I shall be still better pleased to have you accompany me, as my guests, to Petrograd, for which port I am bound." Lord Hastings turned to Jack. "What do you say?" he said. "Would you like to see Petrograd--or St. Petersburg, as it was called before the outbreak of the war?" "Very much, sir," replied the lad, "if Frank can come along." "I guess that can be managed," was the reply. Lord Hastings turned to the Russian commander. "Is there a safe place where I may leave my submarine?" he asked. "It shall follow us, and be one of us," was the reply. "In that case," said Lord Hastings, "we shall be glad to accompany you." The Russian bowed. "Then," said Lord Hastings, "if we may trouble you to set us aboard our own vessel, we shall follow you at a respectable distance. Besides, I should be pleased to have you come aboard, for I can promise to show you such a submarine as it has never been your pleasure to see before." "I shall accept that offer with pleasure," replied the Russian. Calling his first officer, he ordered that a boat be lowered, into which they all stepped and were soon upon the bridge of the D-16. Frank received his commander and his chum with unfeigned delight, for he had been greatly worried about them. "It was all my fault," the Russian commander said. "As your commander told me, I was thick-headed. I am sorry." "Say no more about it," declared Lord Hastings. "Mistakes will happen." All descended below, and, the Russian commander expressing a desire to go beneath the sea, the D-16 submerged. Then Lord Hastings conducted the Russian on a tour of inspection of the vessel, and explained its mysteries to him. The Russian was charmed, and all sat and talked long into the night. It was almost noon of the second day when the D-16, still following in the wake of the Russian cruiser, anchored in the harbor of Petrograd. "I shall be pleased," said Lord Hastings, "to pay my respects to Czar Nicholas." "I fear," said the Russian, "it may be impossible, for he is very busy these days with affairs of state." "Nevertheless," said Lord Hastings, "I have his command to always present myself when in Russia." "In that case," said the Russian, "it is, of course, different."