Related Clues:

• Mata Hari, notably
• He came in from the cold
• Bug someone's phone, e.g.
• ___ ring
• Le Carré character
• Covert agent
• Plant of a sort
• Be a mole
• Maxwell Smart, e.g.
• Stratego piece (3)
• Bond, e.g
• Washington D.C.'s International ___ Museum
• Government agent
• Watch furtively
• Mole, for example