Westminster Abbey

1. The thief is trying to send messages to Sherlock.
2. He wouldn't want his messages to be visible to everyone, now would he?
3. Have you visited the British Museum yet?
4. The book on the table in the British Museum contains a clue that will help you.
5. There is some invisible writing on some of the tombs.
6. When you make a rubbing, the invisible ink is transferred onto the back of the paper.