Related Clues:

• Liberal in first class provides back story perhaps
• Helpful sign
• Campaigner drops pagan abomination
• Logic-based board game
• The greatest supporting film has one watertight storyline
• "I was at my friend's all night," e.g
• You're reading one
• Help in solving
• The dog that didn't bark, perhaps
• It has nine rooms
• Crossworder's need
• Theft, e.g
• Detective's delight
• Basis of a whodunit
• Detective is always looking for it in strange movie about last commandment