Liu et al. review the organization and function of the superior colliculus (SC) across species and emphasize its importance in modulating innate defensive behavior evoked by visually threatening stimuli. In this cover image, a comet hitting the surface of an Earth-like human’s head is symbolic of visually threatening stimuli. The stream in the shape of the neural network around the neck is reminiscent of a long stretch of history. Combined with species above the river, including escaped fish, mice, non-human primates, and humans, this picture suggests that the SC plays a vital, evolutionally-conserved role in processing life-threaten cues. See pages 1519–1540. (Cover designed by Feng Wang, Xue Liu, Hongren Huang and Jialin Ye at SIAT).