"See if you can get it; and meanwhile I'll go up into Mrs. Burbank's room."
The butler showed the way up-stairs and left the Master of Mysteries alone. Once the door was shut, Astro gave a swift look about the chamber, then walked to a writing-desk. Everything was in order, and not a letter was visible. From here he turned to the open grate. The fire was out, and only a few ashes remained. These he examined carefully. On the top were a few flakes of carbonized paper, crumpled like black poppy petals. With a deft finger he drew these from the grate and carried them to the desk, placing them on a white blotter. On the wrinkled surface, almost invisible, were some traces of writing, appearing as if slightly embossed on the surface. He could make out only one word, or part of a word: "Kellem." The closest scrutiny revealed no more writing; but on one charred fragment he discovered the remains of a postage-stamp. It was curiously shrunk to half-size, and appeared as a negative, in which all that had been white was black, and the red ink changed to gray.
By the time he had accomplished this delicate manipulation, the butler had returned.
"I found the letter, sir; but it hasn't been opened at all. It seems that the colonel didn't come home last night, and hasn't returned yet. I got it out of William; but he's in a mortal terror, sir, and he wants me to bring it back at once. Do you think it will take you long, sir?"
"About ten minutes; but I shall have to be alone."
"You're not going to open it, sir! It's as much as William's place is worth to be caught at this game."
"No, I won't open it. I only wish to see the writ-
