Read it through once

“I think that this should do,” said he, glancing into the glass above the fireplace. “I only wish that you could come with me, Watson, but I fear that it won’t do. I may be on the trail in this matter, or I may be following a will-o’-the-wisp, but I shall soon know which it is. I hope that I may be back in a few hours.” He cut a slice of beef from the joint upon the sideboard, sandwiched it between two rounds of bread, and thrusting this rude meal into his pocket he started off upon his expedition.