"And the Baron did not trust him," said Heinrich, reflectively. "If he was not one of us, how came he to be killed?"

"God knows." Miller threw out his hands in a hopeless gesture. "I don't."

"But there must be some motive for the crime," argued the chauffeur. "Miss Kathleen must have suspected something before taking …" Powerful hands on his throat choked his utterance.

"Never mention Miss Kathleen's name in that connection again," commanded
Miller, his voice low and stern. "You hear me, you dog!" and he shook
Heinrich until his teeth rattled, then released him.

"Pardon," gasped the badly frightened man. "I meant no offense."

"See that you follow my instructions hereafter."

"Yes, sir"—Heinrich caressed his throat tenderly, and looked at Miller with a new respect. "I was only going to mention, sir, that Mr. Spencer meddled in what did not concern him. I believe he suspected what I have come to believe."

"And what is that?"

"That this photography business is only a blind."

"A blind?" Miller looked thoughtfully at his companion. "Suppose you pull up a chair; wait, first hang your cap over the keyhole of the hall door." While waiting for Heinrich to follow his instructions Miller seated himself. "A blind?" he repeated. "No, no, Heinrich, you are mistaken; Mr. Whitney has invented a very perfect aeroplane camera, of that I am thoroughly convinced. And our country needs it…."