“Where is the letter?” Harleston asked.

“Locked in the burglar-proof safe in my office.”

“Who knows the combination?”

“Spendel, my confidential clerk.”

“Trustworthy?”

“I would as soon suspect myself.”

“Very good!  Now, another thing:  do you know Fred Snodgrass, an ex-Captain of the Army, who lives at the Boulogne?”

“Casually,” said Carpenter.

“Ever suspect him of being in the German pay?”

“No.  However, he is an intimate friend of Von Swinkle, the Second Secretary—­if that’s any indication.”

“Rather the reverse, I should say.  However, he met Madeline Spencer yesterday in Union Station.  The meeting was apparently accidental, and so far as his shadow could see or hear was entirely innocent.”

“I distrust the apparently accidental and the entirely innocent—­in diplomacy,” Carpenter remarked.  “We should keep an eye on Snodgrass.”

“Meanwhile what are you doing as to the French key-word—­trying for it?” Harleston asked, going toward the door.

Carpenter nodded.  “I’ve got my lines out.  I hope to land it in a few days.  If Marston has it, or gets it earlier, so much the better for us.”

Harleston had walked a block before he recollected that he was obligated to Ranleigh to go in a taxi.  The one in which he had come from Headquarters he had dismissed, not knowing how long he would be at Carpenter’s, and he had neglected to telephone for another.  He would not go back to Carpenter’s; and, anyway, it was nonsense always to be guarding himself from the enemy.

He had not a thing they wanted, nor did he know aught that would be of use to them; and his directorship of the affair was not of great importance; another, if he knew the facts, could take his place and see the matter through.  That was the important point, however.  Time was exceedingly material; and if the Spencer gang caused him to disappear for a few days, they would have a free hand until Ranleigh or Carpenter awoke to the situation.  It was not exactly just to the cause for him to take unnecessary chances.  A drug store was but a short distance up the street, on the other side; he would telephone from it for a taxi.

A moment later, with the honk of a horn, a yellow taxi rounded the corner and bore his way.

He raised his stick to the driver, in event of him being free—­and stepped out from the sidewalk.

The man shook his head in negation and the machine flashed by—­leaving Harleston staring after it with a somewhat surprised and very much puzzled frown.

Madeline Spencer was in the taxi—­alone.  Furthermore, she had not seen him.

XVIII

DOUBT

At N, the next cross-street, the taxi turned west.  Instantly Harleston made for the corner.  When he got there, the machine was swinging north into Connecticut Avenue.  He ran down N Street at the top of his speed.  When he reached the avenue the car was not in sight, nor was there any one on the street as far as Dupont Circle; and as thoroughfares radiate from the Circle as the spokes of a wheel from the hub, the taxi could have gone in practically any direction.