"So that's what really happened," Lestrade said after Sherlock was done telling his story. 

"Yes, exactly as I said." Sherlock looked at John and smiled. A sad smile. "You know, there is just one thing I can not figure out."

"What?" John asked Sherlock. 

"Why was your child at Mrs. Hudson's?"

John furrowed his brows and took a sip. "I love Mrs. Hudson. Trust her with my life. Why wouldn't I trust her with my kid?"

"No," Sherlock sighed. "Not why she was at Mrs. Hudson's, just why she wasn't at home."

"Oh. Well... I got this email. We had gotten a special table at a restaurant later that evening, Anderson actually had a reservation but couldn't make it, so he gave it to Mary and I. Now it makes sense because he knew what was going to happen."

"Hmm..." Sherlock nodded, understanding.

Lestrade and Anderson looked at the two of them, wondering why they were sharing such random questions.

"What's the other question?" Anderson asked. When everyone looked at him, he replied cautiously. "You just... look like there is more to understand, more that you want to know."

Sherlock looked at the ground. "How did you know?"

"Know what?" Lestrade asked.

"Pentonville Prison, Bank of England, the White Tower. They all get broken into and instead of you going over to them, you are at the Watson house, waiting for the perfect time...?"

Lestrade took a swig of his beer. "I knew there was something... off about her. I still can't believe she murdered all those people. She was the one that committed all those crimes. Yes, she was smart, but her craziness explains how she could figure out the answers so fast. She committed all those crimes that she solved, and even killed her friend. I mean...", he took a swig of beer, "She's been working for Moriarty this whole time! And none of us even realized! Wouldn't you think that we would have noticed something was up? And all the things she said... take them and think about them in a different perspective... we should have noticed. She even drugged herself just for the cause-- I bet that's not the worst she has done. Sherlock, how could you not notice what was happening? She was crazy, insane, and we all just..."

"Okay, okay, enough about that," Sherlock turned his attention to John. "How did you know he was there?"

"As you recall, Mary and I just came back from a walk. You think I would not notice that my street was too quiet? That was suspicious, so the whole time, I kept an eye out on what was happening outside the window, when I heard a car. It stopped outside the house and was moving very slowly, you did not even hear it because it was trying to be stealthy. Had to be Lestrade."

"And if it was not?"

John shrugged. "Glad it was Lestrade, then."

"But why would you pay so much attention?"

He shrugged again. "A great man once said that the world is full of obvious things which nobody by any chance ever observes. Well, I decided to think, and observed instead of only seeing."