The plot tells of how an armed robbery takes place on the bus line connecting the airport with various cities in the vicinity of Barcelona. The upshot is that three assailants are dead and one person has an arrest warrant on his head, with six witnesses unable to identify the fugitive. Officer Fran Garza (played by Pablo Molinero) and his professional partner – and ex – Rebeca Quirós (Ana Polvorosa) suspect that the witnesses are not telling the truth: they all claim not to have seen the killer’