Clue

Several Mysterious Clues. (GAME: Elemental, my dear Doctor ^[+]Loading...["Elemental, my dear Doctor (episode)"])

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When she first encountered him, Donna Noble had no clue who the Fourteenth Doctor was. (PROSE: The Doctor's Busiest Day ^[+]Loading...["The Doctor's Busiest Day (short story)"])

Mysterious Clues were used during the Victorian era. (GAME: Elemental, my dear Doctor ^[+]Loading...["Elemental, my dear Doctor (episode)"])