Possible Clues:

• Spirits such as Aladdin's
• Lowdown on the team's spirits
• Contents of special lanterns
• In the beginning, here one finds spirits
• Book's second chapter briefly describes local spirits
• Twins dropping note to one or more spirits
• The sort of spirits that come in bottles
• One repeatedly after information found in Arabian tales
• Spirits of the first verse in the book
• Info on eleven spirits