“It is difficult,” said the prince patiently, “most difficult for me to make myself intelligible to you—­as difficult, if you will forgive me, as if you were to try to explain calculus to one of the street boys outside.  But directly your phase of civilization has opened to you the secrets of the Fourth Dimension, much will be discovered to you which you do not now discern or dream, and among these, Yaque.  I do not jest,” he added wearily, “neither do I expect you to believe me.  But I have told you the truth.  And it would be impossible for you to reach Yaque save in the company of one of the islanders to whom the secret is known.  I can not explain to you, any more than I can explain harmony or colour.”

“Well, I’m sure,” cried Mrs. Hastings fretfully, “I don’t know why you all keep wandering from the subject so.  Now, my brother Otho—­”

“Prince Tabnit,”—­Olivia’s voice never seemed to interrupt, but rather to “divide evidence finely” at the proper moment—­“how long will it take us to reach Yaque?”

St. George thrilled at that “us.”

“My submarine,” replied the prince, “is plying about outside the harbour.  I arrived in four days.”

“By the way,” St. George submitted, “since your wireless system is perfected, why can not we have news of your island from here?”

“The curve of the earth,” explained the prince readily, “prevents.  We have conquered only those problems with which we have had to deal.  The curve of the earth has of course never entered our calculation.  We have approached the problem from another standpoint.”

“We have much to do, Prince Tabnit,” said Olivia; “when may we leave?”

“Command me,” said Prince Tabnit, bowing.

“To-morrow!” cried Olivia, “to-morrow, at noon.”

“Olivia!” Mrs. Hastings’ voice broke over the name like ice upon a warm promontory.  Mrs. Hastings’ voice was suited to say “Keziah” or “Katinka,” not Olivia.

“Can you go, Mr. Frothingham?” demanded Olivia.

Mr. Frothingham’s long hands hung down and he looked as if she had proposed a jaunt to Mars.

“My physician has ordered a sea-change,” he mumbled doubtfully, “my daughter Antoinette—­I—­really—­there is nothing in all my experience—­”

“Olivia!” Mrs. Hastings in tears was superintending the search for both side-combs.

“Aunt Dora,” said Olivia, “you’re not going to fail me now.  Prince Tabnit—­at noon to-morrow.  Where shall we meet?”

St. George listened, glowing.

“May I have the honour,” suggested the prince, “of waiting upon you at noon to conduct you?  And I need hardly say that we undertake the journey under oath of secrecy?”

“Anything—­anything!” cried Olivia.

“Oh, my dear Olivia,” breathed Mrs. Hastings weakly, “taking me, at my age, into this awful place of Four Dimentias—­or whatever it was you said.”

“We will be ready to go with you at noon,” said Olivia steadily.