Recent stories, fears and oblivion seen through a metaphor. A 30-passenger convoy vanishes in the closed circuit of the Buenos Aires underground system. Research will be initiated towards finding the cause of this dematerialization. A young topologist (surfaces mathematician) leads the investigation based on some lost maps and technical data sheets. He cannot find the whereabouts of the old scientist who designed the intricate weft of the subway web, until the unexpected aid from a young girl will ease the obtention of the first clues. Everyting seems to be futile, but a random event that will risk his life gets him into an impossible train, were he will face up the amazing final revelation.