The plot is set in nighttime Sofia in the mid-80s. Bus number 108 makes its last course to the Lyulin district. A brief argument between passengers at the last stop escalates into a beating and leads to the death of one of them. Investigating the criminal atrocity, criminal police operatives are confronted with human indifference. However, thanks to the hard work of investigator Milanov and his young assistant Kolev, the noose around the brazen assasins gradually tightens.