The cousins left the palace together and walked a little way down the street, before either spoke.  Then Sant’ Ilario stopped short.

“Does it strike you that we have undertaken rather a difficult mission?” he asked.

“A very difficult one,” answered San Giacinto.

“Rome is not the largest city in the world, but I have not the slightest idea where to look for that child.  She certainly left our house.  She certainly has not returned to her own.  Between the two, practically, there lies the whole of Rome.  I think the best thing to do, will be to go to the police, if any of them can be found.”

“Or to the Zouaves,” said San Giacinto.

“Why to the Zouaves?  I do not understand you.”

“You are all so accustomed to being princes that you do not watch each, other.  I have done nothing but watch, you all the time.  That young lady is in love with Monsieur Gouache.”

“Really!” exclaimed Sant’ Ilario, to whom the idea was as novel and incredible as it could have been to old Montevarchi himself, “really, you must be mistaken.  The thing is impossible.”

“Not at all.  That young man took Donna Faustina’s hand and held it for some time there by the piano while I was shutting the windows in your drawing-room.”  San Giacinto did not tell all he had seen.

“What?” cried Sant’ Ilario.  “You are mad—­it is impossible!”

“On the contrary, I saw it.  A moment later Gouache left the room.  Donna Faustina must have gone just after him.  It is my opinion that she followed him.”

Before Sant’ Ilario could answer, a small patrol of foot-gendarmes came up, and peremptorily ordered the two gentlemen to go home.  Sant’ Ilario addressed the corporal in charge.  He stated his name and that of his cousin.

“A lady has been lost,” he then said.  “She is Donna Faustina Montevarchi—­a young lady, very fair and beautiful.  She left the Palazzo Saracinesca alone and on foot half an hour ago and has not been heard of.  Be good enough to inform the police you meet of this fact and to say that a large reward will be paid to any one who brings her to her father’s house—­to this palace here.”

After a few more words the patrol passed on, leaving the two cousins to their own devices.  Sant’ Ilario was utterly annoyed at the view just presented to him, and could not believe the thing true, though he had no other explanation to offer.

“It is of no use to stand here doing nothing,” said San Giacinto rather impatiently.  “There is another crowd coming, too, and we shall be delayed again.  I think we had better separate.  I will go one way, and you take the other.”

“Where will you go?” asked Sant’ Ilario.  “You do not know your way about—–­”

“As she may be anywhere, we may find her anywhere, so that it is of no importance whether I know the names of the streets or not.  You had best think of all the houses to which she might have gone, among her friends.  You know them better than I do.  I will beat up all the streets between here and your house.  When I am tired I will go to your palace.”