Possible Clues:

• Hamlet's interrogative after 'How now!'
• Smell — (be suspicious)
• Lilian Jackson Braun's 'The Cat Who Smelled ___'
• Smell ___ (2 words)
• "I smell ---"
• ''I smell ---''
• "I smell ---!" (sense wrong)
• Smell ___ (be wary)
• Smell ___ (sense wrong)
• Smell __ (sense wrong)