[Illustration:  sketch of clue]

Pendleton bent over the result under the flare of the gas light; and as he looked his eyes widened.

“Why,” cried he, “they look like a stenographer’s word-signs.”

“Good!” said Ashton-Kirk.  “And that, my dear fellow, is exactly what they are.  There, scrawled erratically in dripping tallow, is a three word sentence in Benn Pitman’s phonetic characters.  It is roughly done, and may have occupied some minutes; but it is well done, and in excellent German.  I’ll write it out for you.”

Then he wrote on the pad in big, plain Roman letters: 

    HINTER
    WAYNE’S
    BILDNISSE

“There it is,” said the investigator, “done into the German language, line for line.  Brush up your knowledge now; let me see you turn it into English.”

Pendleton, whose German was rusty from long disuse, pondered over the three words.  Suddenly a light shot across his face; then his eyes were in a blaze.

“Behind Wayne’s Portrait!”

He fairly shouted the words.  Astonishment filled him; he was trembling with excitement.

“By Heaven,” he gasped, “you have it, Kirk.  Now I understand the smashing of the portraits of General Wayne.  There was something of value hidden behind one of them—­between the picture and the back!  But what?”

“It was nothing of any great bulk; the hiding place indicated points that out, surely,” said Ashton-Kirk, composedly.  “A document of some sort, perhaps.”

Pendleton stood for a moment, lost in the wonder of the revelation; then his mind began to work once more.

“But I can’t understand the writing of the thing upon the step,” said he.

“It was the fact that it was written that proved to me that there were at least two men concerned.  One knew the hiding place of the coveted object; and this is how he conveyed the information to his companion,” pointing to the step.

“But,” protested Pendleton, “why did he not put it into words?  Surely it would have been much easier?”

“Not for this particular person.  As it happens, he was a mute.”

Again Pendleton’s eyes opened widely; then recollection came to him and he said: 

“It was Locke—­the man concerning whom you were making inquiries of the railroad conductor!”

Ashton-Kirk nodded, and replied.

“And it was he who shrieked when the door of the showroom opened.  The out-cry of a deaf-mute, if you have ever heard one, has the same squawking, senseless sound as that of a psittaceous bird like the parrot or cockatoo.”

“But,” said Pendleton, “the fact that the man who scrawled these signs upon the step was a deaf-mute, scarcely justifies the eccentricity of the thing.  Why did he not use a pencil, as you have done?”

“I can’t say exactly, of course.  But did it never happen that you were without a pencil at a time when you needed one rather urgently?”