Translated from Chinese, this essay by the painter and scholar Liu Wendong examines the supernatural dimension of blue-green (qinglü) mountain and water painting. Citing Bertrand Russell’s remark that the sciences developed from what is most remote to what is nearest, the author suggests that shanshui painting likewise evolved from a cosmic consciousness of space towards individual expression, and that its early favourite subject was the realm of immortals. Ancient reverence for mountains, as places of awe and as inexhaustible treasure-houses inhabited by deities and immortals, shaped this imagery. Zhuangzi’s “Carefree Journey” (Xiaoyao you) supplied the core concepts of “wandering” and the “journey outside this world”, together with the ideals of eternal life and free ascension, which liberate the individual from the limits of time and space. Blue-green painting thus became an ideal schema for seeking immortals, in which the dwellings of mortals and immortals are not separated. The essay also links its maturation to court palace painting and to Li Sixun and Li Zhaodao, who standardised the gold-green and blue-green “immortal” style. The author regrets that science and sketching from life have weakened this imaginative freedom, and calls for reviving an “unconstrained” approach alongside realist methods.