The scent trail as an evidentiary method in criminal proceedings was invented in the USSR and subsequently developed by the East German secret police and widely used against opponents of the regime. Since the 1980s, it has become a common part of police and judicial practice, even in the post-communist Czech Republic. Zuzana Piussi’s latest film continues the director’s investigative work dealing with the problematic construction of reality and dead ends in Central European justice. It follows the fate of people who seek retrials of unfair court proceedings and, in the wake of this, asks whether the method of proving the presence of a person at a crime scene based on the scent detected by a dog is really impartial or how it is possible that a scent trail is often sufficient as the only evidence to convict suspects, even though it is questioned by scientists.