Possible Clues:

• Ringer for dead king and girlfriend?
• Funeral-bell
• By the sound of it, it might have been for little Nell in the end
• Ominous sound
• Solemn sound from king and his mistress
• 'The curfew tolls the . . . . . of parting day' (Gray)
• That would sound for the little end of her in Dickens
• Gloomy ring
• Ring ominously
• Sound of funeral bell