The Bárbara de Braganza prepares to set sail from Argentina to Mexico but, first, Eva is asked to help undercover agents find a man harboring a virus.

When a serious crime occurs aboard the ship, Fabio warns Eva their mission is getting dangerous. Carolina becomes entangled in the mystery.

As the crimes continue, Eva's involvement raises suspicions. Fabio distrusts Carolina. The crew begins to have doubts about the captain's abilities.

When Fabio gets detained, Eva tries to find Steve's photograph. Carmen's prisoner attempts an escape.

The Bárbara de Braganza is attacked on multiple fronts just as the virus starts spreading and the passengers and crew attempt to procure a vaccine.