"Well, Millie, you must make up your mind! Do you accept the order?" cried Carol Mayne.

"I should like to come down and look at the site before I finally say Yes," said she. "And ask Captain Brooke all manner of questions."

"That will suit me well," he replied gravely. "To-day is Monday. Shall we say Thursday?"

CHAPTER XXI
MIRAGE

"He who has seen a city in the skies
Knows he may never cool his tired eyes
At the fair waters of that Paradise.

But the one moment when he thought his feet
Would enter that dream-city, was so sweet
That he can bear the noonday and its heat."
—ALICE HERBERT.

The sky was clear and starry; the night was swept by the strong, clean current of the March wind, as the three men stepped out into Collis Square.

"How shall we get back?" asked Burmester, lighting his cigar. "Train, tube or bus?"

"I shall walk," said Brooke, with brevity.