Reel and Bitter Sky represent two distinct stylistic periods in Caro’s sculpture. Bitter Sky, made almost two decades after Reel, is characteristically darker, vertical, planar, and more architectonic. Bolts and seams joining the assemblage parts remain clearly visible; integrated seamlessly into the whole structure, they are not “hidden” as in the earlier work. Bitter Sky reflects Caro’s renewed interest in the heritage of Cubism, with its overlapping planes and volumes and explorations of volume and mass in space—precisely those issues that he rejected two decades earlier in works such as Reel.