Chance at the last moment will have to dictate.

But from every one of you I must have co-operation, and it can only be by your following my directions implicitly that we can even remotely hope to succeed." He crossed and recrossed the room once or twice before he spoke again, pausing now and again in his walk in front of a large map of Paris and its environs that hung upon the wall, his tall figure erect, his hands behind his back, his eyes fixed before him as if he saw right through the walls of this squalid room, and across the darkness that overhung the city, through the grim bastions of the mighty building far away, where the descendant of an hundred kings lived at the mercy of human fiends who worked for his abasement.
The man's face now was that of a seer and a visionary; the firm lines were set and rigid as those of an image carved in stone--the statue of heart-whole devotion, with the self-imposed task beckoning sternly to follow, there where lurked danger and death.
"The way, I think, in which we could best succeed would be this," he resumed after a while, sitting now on the edge of the table and directly facing his four friends.

The light from the lamp which stood upon the table behind him fell full upon those four glowing faces fixed eagerly upon him, but he himself was in shadow, a massive silhouette broadly cut out against the light-coloured map on the wall beyond.
"I remain here, of course, until Sunday," he said, "and will closely watch my opportunity, when I can with the greatest amount of safety enter the Temple building and take possession of the child.

I shall, of course choose the moment when the Simons are actually on the move, with their successors probably coming in at about the same time.

God alone knows," he added earnestly, "how I shall contrive to get possession of the child; at the moment I am just as much in the dark about that as you are." He paused a moment, and suddenly his grave face seemed flooded with sunshine, a kind of lazy merriment danced in his eyes, effacing all trace of solemnity within them.
"La!" he said lightly, "on one point I am not at all in the dark, and that is that His Majesty King Louis XVII will come out of that ugly house in my company next Sunday, the nineteenth day of January in this year of grace seventeen hundred and ninety-four; and this, too, do I know--that those murderous blackguards shall not lay hands on me whilst that precious burden is in my keeping.