Premise: "The DArkest Knight" is tenth episode of the seventh season of the American mystery–thriller television series "Pretty Little Liars". The installment was directed by Arlene Sanford and written by showrunner I. Marlene King and executive producer Maya Goldsmith. It premiered on August 23, 2016, on the cable network Freeform.
Hypothesis: Arlene Sanford is regularly a director on the show.