A majority of those who reside in the Arceuus House are former humans who, through the power of the Dark Altar, are able to achieve immortality by moving their soul from their mortal body into an incorporeal one. Their souls are freed from the mortal bodies in the crypt below the church, and take on the incorporeal form commonly seen among Arceuus House residents. The Arceuus House is closest to the northern reaches of Zeah, and is the first line of defence against the Wintertodt, a mysterious entity that brings along with it extremely harsh cold.