La Cañada Real, Europe’s largest slum on the outskirts of Madrid, has been without electricity for over a year. Toni, 13 years old and his best friend Nasser have made this neighborhood their playground and adventure. But one day, Nasser tells Toni that he is leaving for France with his family.

This is the story of an undercover investigator who sacrificed everything and risked her life to show the world the harsh reality she experienced over two years inside an animal testing laboratory. Her investigation, which she eventually named 'The Bunker', is captured in hundreds of hours of hidden camera footage that reveals serious cases of animal abuse. Infiltrated in the Bunker is a thriller that exposes the longest infiltration inside a pharmaceutical laboratory in the world, nd puts into perspective while shedding light on an inescapable social debate: the use of animals in scientific experimentation.