“To Prescott—to the murder.” I was nettled. What relation did he imagine I meant?

“Oh, that! None at all!”

I stared incredulously, even more nettled than before. “Sorry to hear that—I had hoped that I had discovered something moderately important.”

“So you did, Bill. But its importance was not exactly in reference to the actual murder.”

“What on earth do you——”

“Its importance is a matter of accumulation—its real relation is to the boot-lace and the Barker I.O.U.”

I shook my head hopelessly. “What can Mary’s letter have to do with those other things—you said yourself we didn’t know to whom the letter was written—besides, we have Mary’s word that she never wrote to Prescott in her life—surely you believe her—you can’t doubt her?”

“Not for a moment, Bill.”

“Well, then”—I became emphatic—“there must be——”

“You’ll see what I’m getting at all in good time. Don’t be impatient—besides, here we are at ‘The Swan’s Nest.’”