With a certain trembling eagerness, Mr. Sinnett watched Mr. Lock draw an envelope from his pocket.

“You can easily put it in a new envelope,” said Mr. Sinnett, as Mr. Lock began to stare perplexedly at the flap.

“I never thought of that,” said Mr. Lock, and at once tore open the missive. It was very short.

I am at 17, Somerset Terrace, Poplar, till to-morrow. Ten my boat sails, but letters there will be forwarded me. Keep to our bargain. Do not forget that I am prepared to pay a higher price than anyone else for it.”

“Strange,” murmured Mr. Lock.

“Seventeen, Somerset Terrace, Poplar,” muttered Mr. Sinnett. “Seventeen, Somer—”

“Do you thing there’s anything in the address, sir?” asked Mr. Lock, curiously.

“If you take my advice,” said Mr. Sinnett, impressively, “you’ll burn that note and say no more about it.”

“I think that would be safest,” agreed Mr. Lock, and, striking a match, ignited the missive in the fire-place.

“Well, I must be going,” said Mr. Sinnett, coming to a sudden briskness; and, settling the score, he hastened away.