"We have decided upon that," said the fourth man. "Czar Nicholas will review his troops before the palace at five o'clock. Ivan and I can get close enough for him to throw with accuracy." "Good. Has it been decided that Ivan is to do the work?" "Yes." "All right. Then we may as well go. Remember, do not speak to Stephan as you go out. It might spoil everything." The men arose, and made their way from the room, without noticing the lads. The latter, being sure they were gone, arose to their feet and followed. "Careful," whispered Frank, as they ascended the stairs. CHAPTER XIX. THE PLOTTERS FOILED. When the conspirators passed through the tobacco shop they did not even glance toward the counter, and therefore did not notice the absence of the shopkeeper. Had they done so, there probably would have been a different story to tell. Frank and Jack, once outside the store, breathed easier, and followed the conspirators at what they deemed a safe distance, nevertheless keeping close enough upon their heels not to lose sight of them should they turn into some place suddenly. "Lucky for us they didn't see what we did to the proprietor of that shop," said Jack. "I should say so," replied Frank. "Now if we can just keep close enough without being discovered," said Frank, "we may be able to find some means of preventing this tragedy." "If they don't stop some place, we are all right," agreed Frank. Jack looked at his watch. "By Jove!" he ejaculated. "What's the matter?" asked Frank. "Why, it's after four o'clock now. There is not much time. Evidently we must be closer to the palace than I thought." "Well, the sooner this is over the better I shall be pleased." "Not losing your nerve, are you?" "Not exactly; still I feel a little uncomfortable." Turning off the narrow side street, the lads followed the men down a much busier thoroughfare, where, at the far end, they could see a great crowd gathered. The men made directly for it, and, approaching closer, the lads recognized the Czar's palace. Right through the large crowd gathered about, the four men pushed their way; then, abruptly they separated into pairs. Jack grasped Frank by the arm. "Quick!" he exclaimed. "You follow those two," pointing, "and I'll take the others. We don't know which one has the bomb." Frank nodded and set out in pursuit of the two moving toward the left. In the crowd there was little danger that the men would notice that they were being followed, and Frank felt safe in crowding right on behind them. Jack followed the same plan with the other pair. The crowd was held back by long lines of troops on either side of the street, spectators not being permitted closer than a hundred feet of the line of march.