Related Clues:

• ''Why, the very ---!''
• It's all in your mind
• Bee Gees album title
• Inventor's need
• Hypothesis
• Brainstorming bit
• Sound of astonishment
• Cerebral creation
• Show surprise
• Think tank output
• Struggle for breath
• Mental picture
• Mental flash
• 'What's the ___?!'
• Betray surprise