When environmental scientists start being murdered by a mysterious assailant in modern day London, the Twelfth Doctor investigates the crimes. While doing so, he enlists the help of his old friend, a certain human named Sarah Jane. Sequel to "From Afar", though that doesn't need to be read to understand this. Part 1 of The Twelfth Hour Series.

The 12th Doctor runs into his old companion, and remembers why Earth means so much to him. Prequel to the Twelfth Hour Series.

Severus Snape lays awake late at night, and wrestles with his demons.