Possible Clues:

• Mystery drink knocked back by English graduate
• 'Puzzle, riddle (6)'
• Could this have the answer to make me gain?
• Gamine being a bit of a puzzle
• 'Mystery, riddle (6)'
• It's a riddle how to make me gain this
• Obscure meaning with note put out in mystery
• Closed book
• WWII encryption machine
• Poser knocking back drink during game that's no good