In episode 5, it's revealed that Peter was killed by the lady of the lake, Viola Willoughby (Kate Siegel), in front of Hannah, Miles, and Flora.

Is Peter Quint dead Bly Manor?

From the get-go, Haunting of Bly Manor didn't hide the fact that the previous governess, Rebecca Jessel, died at Bly Manor. ... But while all that was true, Haunting of Bly Manor kept the full truth away from viewers for quite awhile. As it turns out, Peter was killed by the Lady in the Lake and had become a ghost.

Where is Peter Quint from in Bly Manor?

Quint is Scottish and works for English people, which is obviously a very specific dynamic historically and adds a lot to the character. How did you and Mike settle on that as his origin? It was quite a big thing in building him.