Following his father's steps, Juan Lucas becomes the most famous highwayman in Sierra Morena mountains, also helping local resistance against Napoleonic troops. In love with Ana, a Count's daughter, his hopes seem to have no future.
The strange disappearance of the dogs of his neighbors leads Juan to investigate the case on his own. It ends up finding out that the author of the robberies is a young woman called Eloísa, the cocky daughter of a scientist who uses dogs to create an antidote against sleep. Juan and Eloísa fall...
