Related Clues:

• Purpose — incentive
• Game with Mrs. White and Professor Plum
• 'I was home alone all night,' e.g
• Something dropped in a mystery novel
• Hint, pointer
• Rap-beating story
• Concern for Superman
• Something checked in a case
• Why someone may commit a crime
• Reason second up-and-coming musical is cut short
• Plea of the accused
• This is the answer!
• Excuse one replacing a graduate in panto role
• Game that might end in a library
• Banks on Clintonesque bit of evidence