Possible Clues:

• Inquisitiveness
• It killed the cat, in a saying
• In America, capital no longer invested into municipality -- that's not the norm
• A novel old shop can be fatal for felines
• Killer of cat
• What the dickens sort of a shop might have killed 18 down? (9)
• What made you ask questions about the collector's item?
• Dickens' shop for feline fatality
• Eight lives, before this proved fatal?
• Proverbially, it killed the cat