“He told me that he would let me come with you as your aide-de camp,” he said.  “It—­it’s part of the game.  It makes things easier if we keep up the game.”

It would have attracted attention if they had spent too much time in the vicinity of the big house.  So it happened that the next afternoon the great lady evidently drove out at an hour when they were not watching for her.  They were on their way to try if they could carry out their plan, when, as they walked together along the Rue Royale, The Rat suddenly touched Marco’s elbow.

“The carriage stands before the shop with lace in the windows,” he whispered hurriedly.

Marco saw and recognized it at once.  The owner had evidently gone into the shop to buy something.  This was a better chance than they had hoped for, and, when they approached the carriage itself, they saw that there was another point in their favor.  Inside were no less than three beautiful little Pekingese spaniels that looked exactly alike.  They were all trying to look out of the window and were pushing against each other.  They were so perfect and so pretty that few people passed by without looking at them.  What better excuse could two boys have for lingering about a place?

They stopped and, standing a little distance away, began to look at and discuss them and laugh at their excited little antics.  Through the shop-window Marco caught a glimpse of the great lady.

“She does not look much interested.  She won’t stay long,” he whispered, and added aloud, “that little one is the master.  See how he pushes the others aside!  He is stronger than the other two, though he is so small.”

“He can snap, too,” said The Rat.

“She is coming now,” warned Marco, and then laughed aloud as if at the Pekingese, which, catching sight of their mistress at the shop-door, began to leap and yelp for joy.

Their mistress herself smiled, and was smiling as Marco drew near her.

“May we look at them, Madame?” he said in French, and, as she made an amiable gesture of acquiescence and moved toward the carriage with him, he spoke a few words, very low but very distinctly, in Russian.

“The Lamp is lighted,” he said.

The Rat was looking at her keenly, but he did not see her face change at all.  What he noticed most throughout their journey was that each person to whom they gave the Sign had complete control over his or her countenance, if there were bystanders, and never betrayed by any change of expression that the words meant anything unusual.

The great lady merely went on smiling, and spoke only of the dogs, allowing Marco and himself to look at them through the window of the carriage as the footman opened the door for her to enter.

“They are beautiful little creatures,” Marco said, lifting his cap, and, as the footman turned away, he uttered his few Russian words once more and moved off without even glancing at the lady again.