The sculpture “Cubo” (Cube) by Sérvulo Esmeraldo is rather a set of hints. The two square frames that rest minimally on the ground suggest the presence of a cube with pairs of invisible lines. This cube, partially visible, finally suggests a volume that, magically, can be penetrated. Sérvulo Esmeraldo was born in Crato (CE), in 1929. At the age of 18 he went to Fortaleza (CE), where he began to have orientations in art. Initially he made woodcuts with a popular theme. In 1951 he moved to São Paulo (SP) and in 1957 he held a solo exhibition at the São Paulo Museum of Modern Art. The following year he left for Paris (France), where he studied lithography and attended the School of Fine Arts in Paris. From the figurative, he moved to abstraction and during the 1960s he became involved with kinetic art and sculpture, in a process that led him to perfect the notions of three-dimensionality and volume. Forty of his works can be seen in public places in Fortaleza, where he died in 2017.