Sherlock surprised even himself when he actually laughed. "Lestrade?" He asked, wiping a tiny bit of moisture from his eye. "He is descended from Sir Galahad?"

When John kept a serious lace, his laughter faded. "You really are serious. He is the descendant of Galahad." He was silent for a moment. "Does Greg know? Does know about you.. and about who he is?"

John was serious, and this was becoming a lot more real than he would like it to be. At first he was playing along, but the further they talked, the more he was being drawn in.