Jaime Lorente as Ricardo / Daniel[a] Ramos (Denver): Moscow's son who joins him in the heist.
Esther Acebo as Mónica Gaztambide (Stockholm): one of the hostages who is Arturo Román's secretary and mistress, carrying his child out of wedlock. During the robbery, she falls in love with Denver and becomes an accomplice to the group.
Rodrigo de la Serna as Martín Berrote (Palermo / The Engineer) (part 3–4): an old Argentine friend of Berlin's who planned the robbery of the Bank of Spain with him and assumed his place as commanding officer.
Najwa Nimri as Alicia Sierra (part 3–4): a pregnant inspector of the National Police Corps put in charge of the case after Raquel departed from the force.
Luka Peroš as Marseille (part 4; featured part 3): a member of the gang who joins the robbery of the Bank of Spain.
Belén Cuesta as Julia (Manila) (part 4; featured part 3): godchild of Moscow and Denver's childhood friend. She is a trans woman who joins the gang and poses as one of the hostages during the robbery of the Bank of Spain.
Fernando Cayo as Colonel Luis Tamayo (part 4; featured part 3): a member of the Spanish Intelligence who oversees Alicia's work on the case.
Roberto Garcia Ruiz as Dimitri Mostovói / Radko Dragić[b] (Oslo) (part 1–2; featured part 3–4): a veteran Serbian soldier and Helsinki's cousin.
Fernando Soto as Ángel Rubio (part 1–2; featured part 3–4): a deputy inspector and Raquel's second-in-command.
Juan Fernández as Colonel Luis Prieto (part 1–2; featured part 3–4): a member of the Spanish Intelligence who oversees Raquel's work on the case.
Anna Gras as Mercedes Colmenar (part 1–2): Alison's teacher and one of the hostages.
Fran Morcillo as Pablo Ruiz (part 1): Alison's schoolmate and one of the hostages.
Clara Alvarado as Ariadna Cascales (part 1–2): one of the hostages who works in the Mint.