Read it through once

He nodded assent, and pulled out his thief-dreaded watch, and asked me where I was going to dine? I replied at my own chambers, with Herbert. As a necessary sequence, I asked him if he would favour us with his company, and he promptly accepted the invitation. But he insisted on walking home with me, in order that I might make no extra preparation for him, and first he had a letter or two to write, and (of course) had his hands to wash. So I said I would go into the outer office and talk to Wemmick.