So Vile a Sin

So Vile a Sin is an original novel written by Ben Aaronovitch and Kate Orman and based on the long-running British science fiction television series Doctor Who. It features the Seventh Doctor, Chris and Roz, Bernice, Jason, and Kadiatu Lethbridge-Stewart. It is the conclusion of the "Psi Powers series" and the last appearance of Roz Forrester.