The intersection between national and family memory is shown in this documentary that arises from a discovery made by the filmmaker after the death of his grandfather: a notebook with the memories of his great-grandfather Eloy, imprisoned in Soria during the Civil War for being part of the National Confederation of Labor (CNT). Following in the footsteps of his revolutionary path, Los cangrejos is an exercise in reconstruction based on the voices silenced in a region that, although far from the battle front, carries with it the wound of oblivion and the echo of repression.