- The titular children are ghosts that are trapped there. Although the children themselves are benevolent, there's a tree in the garden which the children called "Green Noah", inhabited by a demonic tree-spirit. The little poem about Green Noah is especially creepy:
Green Noah, demon tree,Evil fingers can't catch me!
- In the fifth book, when Melanie sends a curse to Tolly's grandmother, carved on the skin of a child's hand.
- The maggots and snakes also count as this.
- The scene in the sixth book, when the Saxons are slaughtering the Britons.
Nightmare Fuel / The Green Knowe Chronicles
The Green Knowe Chronicles by Lucy M. Boston is about a boy who ends up being sent to live at an old gothic manor. Strange things are afoot, however...