"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.
The title "The DArkest Knight" uses intentionally placed capital letters to allude to a deeper meaning than it would indicate normally
It's fair to say that the show-writers meant to communicate something latent when they capitalized the A in "The DArkest Knight"