The Eaters of Light" is the tenth episode of the  of the British  series . It is written by  and was broadcast on 17 June 2017 on . "The Eaters of Light" sees the return of a writer from the classic era of the programme, making her the only writer to date to have worked on the classic and revived eras of the show; the episode received mixed reviews from television critics.  () takes  () and  () to the Scotland in the second century to settle their different theories about what happened to the ninth legion of the Roman army that vanished. When they arrive, however, they find an alien menace from another dimension that may be the reason behind the vanishing, but is a far greater threat than any army.