The phrase 'Crossing brook lain fairy' evokes an image of a mystical or enchanted scene. The word 'brook' suggests a small stream or creek, while 'lain' implies something lying down or resting. The inclusion of 'fairy' introduces an element of fantasy or magic, suggesting the presence of a mythical creature. This brief line might be interpreted as a moment of crossing into a magical realm, where the ordinary world meets the extraordinary. The imagery of a fairy by a brook can symbolize nature's enchantment and the allure of the unknown. Without additional context, the meaning remains open to interpretation, inviting readers to imagine their own narrative or emotional response to this evocative scene.