Amparo unravels a 30-year-old blackmail fiasco, revealing a darker side to the Expo. Joined by Richi and Robledo, she searches old archives for clues.

Reeling from yet another tragedy, Amparo and Carmen join forces and look into Rosa's past. A shaken Richi stumbles upon a vital piece of information.

As a explosion harms an unintended victim, Richi and Amparo track down a key player from the Expo, while Robledo teams up with a forensic investigator.

When Amparo's husband is killed in a massive explosion, a strange figurine suggests it was not an accident, so she turns to a haunted ex-cop for help.

Frustrated by police inaction, Amparo travels alone to Seville, where a stranger warns her to stay away while the killer prepares to strike again.

Palacios attempts to buy his safety; but as the killer's bloody vendetta reaches its crescendo, the race to stop him takes a high-speed turn.