The sculptor Alexander Calder (1898-1976) and the painter Joan Miró (1893-1983) first met in Paris in 1928 and became life-long friends. This original and visually stunning book places the mobile sculptures of Calder alongside the poetical paintings of Miró and provides fresh insights into the visual dialogue between these two artists. What did the painter see in the sculptor? What did the sculptor see in the painter? These questions are answered through an extensive examination of the exchange of artwork and correspondence between the two artists, maintained across two continents and through the turmoil of war.