"Come on!" urged Grundt, scowling. "I have given you a respite. But I now grow impatient...."
I noticed that the ague had taken him again and that, do what he might, he was trembling violently all over.
"If you will allow me to put my left hand in my jacket pocket," I said, "I can show you something that will explain everything."
"Bitte sehr! But remember that I can stretch you dead before you will have time to shoot, even through your pocket...."
From my jacket I produced the little mirror. The sun caught its polished surface as I brought it out and it flashed and flashed again.
Between the curving arms of Horseshoe Bay the launch of the Naomi came flying. I could see the white spray thrown up in two curving sheets as her bows cut the green water. To my ears stole faintly the quick chug-chug of her propeller. I wondered if Grundt had heard it. But he was staring fixedly at the little mirror which I kept turning over in my hands so that it flashed and flashed....
"This was wired to the grave, Grundt," said I. "It was what failed you to read the cipher. You remember the line 'Flimmer', flimmer' viel'? That was the indication to throw a spot-light thus!"—I caught the sun's rays in the glass and flashed it seaward to the bay——"from the mirror set at an angle of 85 degrees; 'the garrison of Kiel,' 'die Fünf-und-Achtziger', you know, Herr Doktor! Incidentally it was you yourself who were good enough to recall the allusion to my mind!...."
And I reminded him of our talk in the ravine in the forest.
Savagely he bit his lip.
"So that was what made you willing to hand me the message," he commented. "I wondered what it was. But continue! We waste valuable time!...."