A felled tree, sawn into planks and raised into the walls of a new house, may still carry its old tenant in the timber; and unless the builder makes his peace, the wood-spirit lodged in the beams will turn on the people who sleep beneath them. The most vivid witness on our shelf is The Golden Bough: A Study in Magic and Religion (published 1922), the comparative study of James Frazer, whose survey of tree-worship follows the spirit indoors. The people of Nias, he reports, hold that a spirit set loose from a dying tree can “cause the death of all the” children, and kill them “in a house by perching on one of the posts that support it”. So the timber must be reconciled. When a Toradja dwelling in Celebes is ready, a goat, pig, or buffalo is killed and every board smeared with blood, that the forest-spirit still hiding there be put in good humour and “do the inmates of the house no harm”. A whole grammar of household appeasement follows — planting no post upside down lest its occupant resent the indignity, and, before ever a tree is felled to build with, coaxing “the spirit who dwells in the tree to change his lodging”.

A second witness gives the being its plain domestic name. In Russian Folk-Tales (published 1873), William Ralston sets the household powers among the beings with which “the old Slavonians peopled the elements” — among them “the Rusalka or Naiad” and, kept nearest the hearth, the Domovoy or House-Spirit. Ralston will not, however, open that drawer here: he says plainly “I will not at present quote any of” the stories in which they figure, sending the reader to another book, so the Domovoy is named on our shelf but not yet told. What the two witnesses share is a single intuition — that a dwelling is inhabited before its people move in, and that living well under a roof means keeping terms with whoever was already there. If the house-spirit is only the wood-spirit who never left the timber, when does a guardian of the hearth become a grievance in the walls?