A caustic satire of many of the 'types' found in Spanish society.

Recounts the experiences of a middle-class family, the Alcántaras, during the last years of the rule of Francisco Franco and the beginning of the Spanish Transition to democracy.

People are dying mysteriously and gruesomely, and nobody has a clue what the cause is. Only health worker Mike Brady has a possible solution, but his theory of killer slugs is laughed at by the authorities. Only when the body count begins to rise and a slug expert from England begins snooping around does it begin to look like Mike had the right idea after all.

The film refers to the "gray neighborhoods", called in Argentina "villas miseria", in which the less qualified workers or those who have recently arrived from the rural areas live in the industrial cordons.