We recently introduced a novel visual motion illusion called the bookend effect (Riga et al., 2025). The name relates to the fact that when a horizontal row of illusory elements (e.g., furrow illusion or double drift elements) physically move together, the perceived illusory direction of the group is strongly determined by the two outer “bookends”, even if the inner “books” have opposite illusory trajectories. We hypothesize that the visual system creates a single, unified object representation due to spatial proximity and shared physical movement, with the more salient bookend elements dominating the perceived motion direction of the entire configuration. The effect does not rely on crowding, as both the static and dynamic features of the inner books can easily be reported. However, those features appear to play little if any role in establishing perceived group direction. Here, we present a novel series of psychophysical experiments to explore how and when the bookend effect occurs, and to assess whether the inner book elements are ever able to exert any influence on the overall group motion. More generally, we believe that the bookend effect has potential to provide new insights into our understanding of “common fate” in the context of illusory motion.