"Why do you keep them?"

"Sorry?" John opened his eyes, turning his head in the direction of the questioner.

"The books. Why keep them?" Sherlock sounded genuinely curious.

John sighed.

"They took my sight Sherlock, but I'll be damned before I let them take my life with it."

There was a sound very like a snort of derision, and John frowned.

"What?"

"Sentiment." The younger man almost spat the word, his disgust at such maudlin emotions evident.

John opened his mouth but his words were forestalled by the sound of his phone ringing. He pulled it from his pocket, his thumb moving with familiar ease to answer the call.

"Yeah mate, what have you got?" John stood and walked out to the kitchen.

"Barrymore knows that his watchers have been spotted, he's pulling them out."

"Hmm, okay."

"And there's no more news on the information leak, I'll keep at it."

"Great. Unfortunately I have another person to consider."

"Who?"

"Sergeant Sally Donovan."

"Christ John…."

"Sorry mate, I know another mole is the last thing you needed to hear, but if you could check it out…"

"I'm on it. Check in later."

The line went dead, and John returned to his seat.

"How did you know who it was?"

"Ringtone; everyone has a different one, so do you prefer Mozart or Beethoven?"