It is the "Head of Akkadian Ruler".
Answer:
They meet up in secret. Their great-great grandparents fought in opposite sides of the war. They will run away and leave notes saying they will only return when they will be allowed to marry. But then as they write the notes, Arlechino misplaces a comma. His mother knows this must be serious because he never does so. So she sets out to find him. As she is walking down the road she gets hit by a car. She then has to go to the hospital. Luckily, she only has a broken rib. After she got hit, though, she passed out and met an angel who told her to let them marry, so she does. They all live happily ever after. THE END.
Explanation:
Brian found the flat stone somewhere between chapters 14 and 17.
