Related Clues:

• Mum's the word
• "Don't tell a soul" reply
• ''Mum's the word''
• "Your secret is safe with me"
• 'Shhhh!' response
• Non-speaking line?
• "I won't tell a soul"
• Smiley's pleader a suspect? I'm not at liberty to say
• I'd keep mum's emeralds and paisley shift
• I'm no whistle-blower, physically incapable of leaking?
• "Your secret's safe with me"
• I have nothing to say to Emerald Isle spy - a revolutionary
• I have to breath through the nose? I'm saying nothing!
• *"I won't tell a soul!"
• Secret assurance