Spy
From Tardis Wiki, the free Doctor Who reference
A spy was an individual who worked in espionage.
The Doctor and/or his companions were accused of being spies on many occasions. Among those who made the accusations included Odysseus and Cassandra (TV: The Myth Makers), General Smythe (TV: The War Games), Brigade Leader Lethbridge-Stewart (TV: Inferno), Ortron (TV: The Monster of Peladon), Tuar (TV: Planet of the Spiders), the Marshal of Atrios (TV: The Armageddon Factor), and Daisy K (TV: The Happiness Patrol).
Kalik believed that Vorg was a spy. (TV: Carnival of Monsters)
William Shakespeare worked as a spy for King James I. (PROSE: The Empire of Glass)