The Governess is distracted from Miles by a horrid development – she grabs the boy and holds him so that he can't see the window, for, outside, Peter Quint appears, glaring in through the windowpane.
Miles, unaware of what's going on behind and around him, admits that he took the letter. The Governess is heartened by this admission. Miles then tells her that he found nothing in the letter, and that he burnt it.
The Governess seizes upon this opportunity to ask about school. She asks the boy if he did, as Mrs. Grose suggested, the same kinds of thing at school.
Miles now admits that he already knew that he could not return to school, now that he knows that the Governess knows. It's not because he stole – rather, it's because he "said things" (24.12). We never hear what kinds of things he said, but they must have been pretty bad if he was asked never to come back.
Miles says that he only said things to those students that he liked – and that they must have in turn said these things to those that they liked.
The Governess, however, isn't content just to speculate about these things. Instead, she presses him more, demanding to know what these things were.
The Governess sees Quint's "white face of damnation" (24.21) once more at the window, and cries out "No more!" (24.21) to him.
Miles, sensing that the Governess is addressing someone else, asks desperately if Miss Jessel is there – the Governess cries that it's not Miss Jessel, but another. She doesn't even refer to Quint as "he," and calls him "it" instead.
The boy, in a fit of something like madness, asks if it's "he," meaning Quint. He then utters the most famous line of the story – "Peter Quint – you devil!" – and spins around to look for him.
The Governess clutches at the boy, trying to tell him that Quint doesn't matter anymore, since he belongs to her now.
Upon looking out the window and seeing nothing, Miles cries out – the Governess catches him and holds him, but realizes that the child, deserted by Quint's spirit, has died.