Related Clues:

• Look through a peephole, perhaps
• "I ___" (early Cosby show)
• World traveler, perhaps
• Intel collector
• Concern yourself with intelligence
• "The ___ Who Loved Me"
• Code user
• Vigilant one
• Secret stealer
• Le Carré hero, e.g.
• Hari or Harriet
• One being unsubtle, perhaps
• KGB worker
• Enemy agent
• Keep watch secretly, maybe for foreign government