“If there is a desperate plot against me, Roseye,” I said, looking straight at her, “then there is, surely, a similar one against you, and also against Teddy. Our enemies are desperate, and they know a good deal—that’s certain. Perhaps they have somehow learnt that we four possess the secret of how the Zeppelin menace can be combated. No secret however is safe from the owner of the Invisible Hand. Hence, if an attempt is made to send me to my death—attempts will also be made against you both.”

“Well—that seems quite feasible—at any rate,” remarked Teddy. “I don’t think Roseye should go up again—just for the present.”

“Certainly not,” I said. “There’s some deep-laid and desperate scheme against us. Of that, I’m now convinced. Our enemies do not mean to allow us to conduct any further experiments—if they can help it.”

“But they don’t know the truth, Claude,” chimed in Roseye.

“No. They are working most strenuously to get at it. That’s quite clear.”

“But who can they be?” asked my well-beloved.

“Ah! That’s a mystery—at least it is at the present. It is a very serious problem which we must seek to solve.”

“But we shall do so, sooner or later, never fear,” Teddy exclaimed confidently. “We hold the secret, and our enemies, whoever they may be, shall never learn it.”

A silence fell between us for several moments.

At last I said: