“Now!” she said.

The car straightened out into a street of stately residences and scuttled along until the placid bosom of the Potomac came into view; beside that for a few minutes, then over the bridge to the Virginia side, in the dilapidated little city of Alexandria.  The car did not slacken its speed, but wound in and out through dingy streets, past tumble-down negro huts, for half an hour before it came to a standstill in front of an old brick mansion.

“This is number ninety-seven,” the chauffeur announced.

Miss Thorne entered the house with a key and was gone for ten minutes, perhaps.  She was readjusting her veil when she came out and stepped into the car silently.  Again it moved forward, on to the end of the dingy street, and finally into the open country.  Three, four, five miles, perhaps, out the old Baltimore Road, and again the car stopped, this time in front of an ancient colonial farm-house.

Outwardly the place seemed to be deserted.  The blinds, battered and stripped of paint by wind and rain, were all closed, and one corner of the small veranda had crumbled away from age and neglect.  A narrow path, strewn with pine needles, led tortuously up to the door.  In the rear of the house, rising from an old barn, a thin pole with a cup-like attachment at the apex, thrust its point into the open above the dense, odorous pines.  It appeared to be a wireless mast.  Miss Thorne passed around the house, and entered the barn.

A man came forward and kissed her—­a thin, little man of indeterminate age—­drying his hands on a piece of cotton waste.  His face was pale with the pallor of one who knows little outdoor life, his eyes deep-set and a-glitter with some feverish inward fire, and the thin lips were pressed together in a sharp line.  Behind him was a long bench on which were scattered tools of various sorts, fantastically shaped chemical apparatus, two or three electric batteries of odd sizes, and ranged along one end of it, in a row, were a score or more metal spheroids, a shade larger than a one-pound shell.  From somewhere in the rear came the clatter of a small gasoline engine, and still farther away was an electric dynamo.

“Is the test arranged, Rosa?” the little man queried eagerly in Italian.

“The date is not fixed yet,” she replied in the same language.  “It will be, I hope, within the next two weeks.  And then—­”

“Fame and fortune for both of us,” he interrupted with quick enthusiasm.  “Ah, Rosa, I have worked and waited so long for this, and now it will come, and with it the dominion of the world again by our country.  How will I know when the date is fixed?  It would not be well to write me here.”

My lady of mystery stroked the slender, nervous hand caressingly, and a great affection shone in the blue-gray eyes.

“At eight o’clock on the night of the test,” she explained, still speaking Italian, “a single light will appear at the apex of the capitol dome in Washington.  That is the signal agreed upon; it can be seen by all in the city, and is visible here from the window of your bedroom.”