A century ago, science created an animal model which would allow it to explore the mysteries of the human brain. This model is the lab rat. Thanks to this rat, major advances have been made. On the neurosciences front, it is today at the centre of key questions: will it be possible to read into our brains? Will we one day manage to control our fears and emotions? Will we be able to control machines by thought or be controlled ourselves by remote control? Before any human experiment, it is these rats that are at the front line of all such revolutionary changes… This film retraces the history of these rodents and their close association with brain and behavioural sciences. It is an investigation that attempts to explain how the big social and philosophical questions of tomorrow could take centre stage in brain laboratories and their special animal model: the rat.