Possible Clues:

• Lake ___ (Blue Nile source)
• Lake ___, source of the Blue Nile
• "In the Woods" author French
• Source of the Blue Nile
• "The Witch Elm" novelist French
• Blue Nile source, Lake ___
• Lake __, source of the Blue Nile
• Blue Nile source lake
• Lake ___, head of the Blue Nile
• Lake from which the Blue Nile begins