Decline in Intelligence Quotient, increase in autism and behavioral disorders: for twenty years, scientific studies show that human intelligence and mental health could be at risk. Why? For many researchers, a small organ is at the heart of the question: the thyroid. For without a minimum of thyroid hormones at the right time, the human baby becomes ... an idiot. Any imbalance in the functioning of the thyroid represents a danger to the brain of the unborn child. But where can this imbalance come from? From an iodine deficiency? From endocrine disruptors, chemical molecules that have invaded our daily lives? Driven by scientists at the forefront of research, the film intends to influence the public debate and focus on a disturbing phenomenon of which no one yet seems to have taken the measure.