Related Clues:

• Austin Powers, e.g.
• Butt in
• Bond, for example
• George Smiley, e.g.
• Secret trader
• One of Smiley's people
• Snoop around
• Mata Hari, for one
• Secret agent
• Use leverage
• Undercover sort
• Mole
• Tail, maybe
• Sight
• Kind of glass