Holmes holds Watson close against his side, and he closes his eyes as Watson confesses this. Of course he's already intuited that Watson felt that way; he still has the mark on his cheek to prove it. It's another to hear it, and another to hear that Watson repents from that. He turns his head to kiss Watson softly before he lays down on the couch, holding his arms out for Watson to join him.

"I'm not sure how I could have lived with myself either," he confesses quietly, his eyes on Watson. "You are my life, my dear. While I was away... When I was living for myself, I nearly destroyed myself. Only when I began to live for you again -- I pulled myself out of the pit where I'd thrown myself."