Lestrade dabbed egg yolk from his chin with his napkin. I stared at him. He did not look like my idea of a police inspector, but then, my friend looked little enough like my idea of a consulting detective-whatever that might be.

“Perhaps we should discuss the matter privately,” Lestrade said, glancing at me.

My friend began to smile, impishly, and his head moved on his shoulders as it did when he was enjoying a private joke. “Nonsense,” he said. “Two heads are better than one. And what is said to one of us is said to us both.”

“If I am intruding-” I said, gruffly, but he motioned me to silence.

Lestrade shrugged. “It’s all the same to me,” he said, after a moment. “If you solve the case then I have my job. If you don’t, then I have no job. You use your methods, that’s what I say. It can’t make things any worse.”

“If there’s one thing that a study of history has taught us, it is that things can always get worse,” said my friend. “When do we go to Shoreditch?”

Lestrade dropped his fork. “This is too bad!” he exclaimed. “Here you were, making sport of me, when you know all about the matter! You should be ashamed-”

“No one has told me anything of the matter. When a police inspector walks into my room with fresh splashes of mud of that peculiar mustard-yellow hue on his boots and trouser legs, I can surely be forgiven for presuming that he has recently walked past the diggings at Hobbs Lane, in Shoreditch, which is the only place in London that particular mustard-colored clay seems to be found.”

Inspector Lestrade looked embarrassed. “Now you put it like that,” he said, “it seems so obvious.”

My friend pushed his plate away from him. “Of course it does,” he said, slightly testily.

We rode to the East End in a cab. Inspector Lestrade had walked up to the Marylebone Road to find his brougham, and left us alone.