Lilith

A young scholar inherits a house with a large, mysterious library. While studying in it, a raven offers to be his guide, leading him into a parallel world 'behind the looking-glass', where earthly laws do not apply and reality is made up of seven dimensions. On his journey through this strange realm, he meets a host of beings, including the beautiful demoness Lilith, and experiences both terrifying and uplifting adventures, the main feature of which are transformations – metamorphoses of body and soul.
Lilith (1895) is the most significant and also the darkest work by the Scottish writer George MacDonald (1824–1905). For Lovecraft, as he wrote in his famous essay 'Supernatural Horror in Literature', it is a novel characterised by its 'compelling bizarrerie'. It is widely regarded as one of the pinnacles of Victorian fantasy and had a great influence on later authors such as C. S. Lewis and J. R. R. Tolkien. It ingeniously combines the tradition of romantic fantasy prose with traditional heroic romance, fairytale adventure, and spiritual allegory.