“You would know these faces wheresoever you saw them?” said the Prince.  “If you passed one in Bond Street or in the Marylebone Road, you would recognize it at once?”

“As I know yours, sir,” Marco answered.

Then followed a number of questions.  Loristan asked them as he had often asked them before.  They were questions as to the height and build of the originals of the pictures, of the color of their hair and eyes, and the order of their complexions.  Marco answered them all.  He knew all but the names of these people, and it was plainly not necessary that he should know them, as his father had never uttered them.

After this questioning was at an end the Prince pointed to The Rat who had leaned on his crutches against the wall, his eyes fiercely eager like a ferret’s.

“And he?” the Prince said.  “What can he do?”

“Let me try,” said The Rat.  “Marco knows.”

Marco looked at his father.

“May I help him to show you?” he asked.

“Yes,” Loristan answered, and then, as he turned to the Prince, he said again in his low voice:  “he is one of us.”

Then Marco began a new form of the game.  He held up one of the pictured faces before The Rat, and The Rat named at once the city and place connected with it, he detailed the color of eyes and hair, the height, the build, all the personal details as Marco himself had detailed them.  To these he added descriptions of the cities, and points concerning the police system, the palaces, the people.  His face twisted itself, his eyes burned, his voice shook, but he was amazing in his readiness of reply and his exactness of memory.

“I can’t draw,” he said at the end.  “But I can remember.  I didn’t want any one to be bothered with thinking I was trying to learn it.  So only Marco knew.”

This he said to Loristan with appeal in his voice.

“It was he who invented ‘the game,’” said Loristan.  “I showed you his strange maps and plans.”

“It is a good game,” the Prince answered in the manner of a man extraordinarily interested and impressed.  “They know it well.  They can be trusted.”

“No such thing has ever been done before,” Loristan said.  “It is as new as it is daring and simple.”

“Therein lies its safety,” the Prince answered.

“Perhaps only boyhood,” said Loristan, “could have dared to imagine it.”

“The Prince thanks you,” he said after a few more words spoken aside to his visitor.  “We both thank you.  You may go back to your beds.”

And the boys went.

XIX

“THAT IS ONE!”

A week had not passed before Marco brought to The Rat in their bedroom an envelope containing a number of slips of paper on each of which was written something.

“This is another part of the game,” he said gravely.  “Let us sit down together by the table and study it.”