This genre painting depicts a scene from Boccaccio's 'Decameron'. The scene is taken from the third tale of the eighth day and depicts three men – Calandrino, Bruno and Buffalmacco – who are on a quest beside the river Mugnone to find a heliotrope (bloodstone) which Calandrino believes will bestow the power of invisibility.

Having found what he believes to be a heliotrope (actually a rock) Calandrino believes himself to be invisible and is heading home with a sack filled with more rocks while his companions play along by pretending not to see him, all the while 'accidentally' kicking stones in Calandrino's direction. Bruno and Buffalmacco were early Renaissance Italian painters who are known far better for their love of practical jokes than for their artistic work and this is probably why Bocccaccio uses them as characters in this tale.