Start of the cube turning inside out. (J.P.Petit & C.Tardy) ... This is the polyhedral version of the initial model of Morin's "tobacco pouch" turning inside out, whose central model is a two-sheet covering of the Boy surface. For the moment (April 2000) I have found only this, but Christophe Tardy was quick to transform my cardboard model into a new element of the virtual-reality bestiary. To be continued, therefore...