Who demands Percy to return the helm and surrender the master bolt?

What does the Nereid give Percy to help him escape the underworld?

What does Percy use to trap Procrustes?

What happens to Los Angeles when Percy and his friends return to the surface?

Who is the owner of the store Percy and his friends escape into?

What does Percy notice about his backpack in the underworld?

What do Percy and his friends use to find the underworld?

Who subdues Cerberus in the underworld?

What does Percy feel emanating from the pit in the underworld?

What does Annabeth offer the taxi driver to drive them to Los Angeles?