As Shirley, with a half-insane light in his eyes, flashed the message mechanically through space, Craig rose and signalled to the house.  Under the portecochere I saw a waiting automobile, which an instant later tore up the broken-stone path and whirled around almost on two wheels near the edge of the cliff.  Glowing with health and excitement, Gladys Shirley was at the wheel herself.  In spite of the tenseness of the situation, I could not help stopping to admire the change in the graceful, girlish figure of the night before, which was now all lithe energy and alertness in her eager devotion to carrying out the minutest detail of Kennedy’s plan to aid her father.

“Excellent, Miss Shirley,” exclaimed Kennedy, “but when I asked Burke to have you keep a car in readiness, I had no idea you would drive it yourself.”

“I like it,” she remonstrated, as he offered to take the wheel.  “Please—­please—­let me drive.  I shall go crazy if I’m not doing something.  I saw the Z99 go down.  What was it?  Who—­”

“Captain,” called Craig.  “Quick—­into the car.  We must hurry.  To the Stamford house, Miss Shirley.  No one can get away from it before we arrive.  It is surrounded.”

Everything was quiet, apparently, about the house as our wild ride around the edge of the harbour ended under the deft guidance of Gladys Shirley.  Here and there, behind a hedge or tree, I could see a lurking secret-service man.  Burke joined us from behind a barn next door.

“Not a soul has gone in or out,” he whispered.  “There does not seem to be a sign of life there.”

Craig and Burke had by this time reached the broad veranda.  They did not wait to ring the bell, but carried the door down literally off its hinges.  We followed closely.

A scream from the drawing-room brought us to a halt.  It was Mrs. Brainard, tall, almost imperial in her loose morning gown, her dark eyes snapping fire at the sudden intrusion.  I could not tell whether she had really noticed that the house was watched or was acting a part.

“What does this mean?” she demanded.  “What—­Gladys—­you—­”

“Florence—­tell them—­it isn’t so—­is it?  You don’t know a thing about those plans of father’s that were—­stolen—­that night.”

“Where is Nordheim?” interjected Burke quickly, a little of his “third degree” training getting the upper hand.

“Nordheim?”

“Yes—­you know.  Tell me.  Is he here?”

“Here?  Isn’t it bad enough to hound him, without hounding me, too?  Will you merciless detectives drive us all from, place to place with your brutal suspicions?”

“Merciless?” inquired Burke, smiling with sarcasm.  “Who has been hounding him?”

“You know very well what I mean,” she repeated, drawing herself up to her full height and patting Gladys’s hand to reassure her.  “Read that message on the table.”

Burke picked up a yellow telegram dated New York, two days before.