Related Clues:

• Perplexer
• It's mind-boggling
• Stumper
• Perplexity
• Riddle
• Mind-boggler
• Real poser
• You, for one
• 'Hmm?' inducer
• Head-scratcher
• Problem
• You, at this very moment
• Baffler (anagram of 52-Across)
• Baffling puzzle
• Cryptic mystery