Possible Clues:

• Coy reply to "You were joking, right?"
• '___ not clear?'
• 'What -- to think?'
• ''Where __?''
• "What __ thinking?"
• "Where __?"
• 'What -- thinking?'
• See 39-Across
• ''Now, where __?''
• 'So ___' (words of agreement)