He sets the white queen on the table, not in the box with the rest. Sentiment. The same thing that made him hesitate on the roof. Always sentiment.

"Caring is not an advantage."
How true, big brother. How true.

But, then. He picks up the black queen and sets it down between the two bottles. He meets Moriarty's eyes, his pale ones calm and steady. It's a challenge.

"I do understand."