Very few police officers access the elite corps of the Spanish National Police. One hundred of them have passed the pre-entry tests for the G.E.O. course, one of the most demanding training courses in the world. In this first episode, the coexistence phase begins at the G.E.O. training camp in Trillo (Guadalajara), where the candidates will experience a frenetic and demoralizing first 24 hours.

The training continues in Trillo. The Tagus continues its relentless selection as the instructors try to get to the core of the trainees, to discover their weaknesses, their strengths, to confront them with their physical and psychological barriers.

Only a month has passed and the physical injuries are starting to take their toll, there are many weeks to go and the fear of having to give up is ever present. In this episode, we get to know more about the candidates and the instructors, their dreams, their motivations and the sacrifices they are willing to make to be part of the G.E.O.

On 11 March, 2004, Spain suffered the first Islamist attack in Europe with the explosion of several bombs on the regional trains at Atocha in Madrid. The G.E.O. was the unit in charge of the police operation that surrounded the members of the jihadist group in an apartment in Leganés and resulted in the suicide of eight terrorists and the death of one member of the unit.

It is day number 84. Of the 100 candidates who started, only 18 remain. The feeling of uprootedness and isolation is already taking its toll on the minds of the trainees. Each one seeks his motivation to continue, whether it be in family, religion, memories or the comradeship within the group itself. They have given their souls to the G.E.O. and there is only one secret to endure: to want it.

The pressure increases. It is important to learn obedience, but also to learn how to be a respected leader. The instructors put the trainees through high-risk situation simulations, such as defending embassies. For police officers, a single moment of hesitation or lack of concentration can trigger a decisive mistake.

Training has moved from a technical background to specialization: tactical assaults on aircraft, offshore boardings, their first parachute jump. They are overcoming trials they could never have imagined, and each small triumph is, for the G.E.O. candidates, justification for all the pain, sacrifice and suffering they are going through.

One year later, of the 100 candidates who entered the G.E.O. selection course, only a few have achieved their dream. But this triumph is just the beginning of a hard life full of sacrifices for them and their families. It has been an unforgettable life journey that has transformed them forever.