Na het verwerken van de dood van zijn broer Sergio, verheugt verpleger Mario zich op een nieuw hoofdstuk in zijn leven met de komst van zijn eerste kind. Maar wanneer kartelbaas Antonio Padin uit de gevangenis wordt ontslagen wordt Mario aangesteld om zorg voor hem te dragen. Al snel begint hij zich af te vragen of zijn zorgplicht belangrijker is dan de levens die deze man heeft vernietigd.
Ja! de film Quien a hierro mata is nu beschikbaar om te kijken op Netflix in Nederland.
| Costume & Make-Up | Silvia Neira | Makeup & Hair Assistant |
| Art | Javier Alvariño | Art Direction |
| Art | Ventura Villar | Assistant Set Decoration |
| Art | Paula Marín | Set Decoration |
| Production | Arantza Vélez | Casting |
| Costume & Make-Up | Erea Pérez | Makeup Artist |
| Costume & Make-Up | Susana Veira | Makeup & Hair |
| Directing | Lorena Vilas | Second Assistant Director |
| Directing | Paco Plaza | Director |
| Writing | Jorge Guerricaechevarría | Writer |
| Sound | Maika Makovski | Music |
| Writing | Juan Galiñanes | Writer |
| Camera | Pablo Rosso | Director of Photography |
| Costume & Make-Up | Vinyet Escobar | Costume Design |
| Production | Emma Lustres | Producer |
| Production | Borja Pena | Producer |
| Production | Mercedes Gamero | Producer |
| Production | Mikel Lejarza | Producer |
| Sound | Kevin Hortigüela | Sound Effects Editor |
| Costume & Make-Up | Nacho Díaz | Special Effects Makeup Artist |
| Costume & Make-Up | Jordi Morera | Special Effects Makeup Artist |
| Editing | David Gallart | Editor |
| Directing | Ana Hernando | First Assistant Director |
| Costume & Make-Up | Alberto Hortas | Special Effects Makeup Artist |
| Sound | Ignacio Arrojo | ADR Recordist |
| Directing | Isa Escrigas | Third Assistant Director |
| Sound | Yasmina Praderas | Sound Mixer |
| Costume & Make-Up | Beatriz Antelo | Hair Designer |
| Sound | Maika Makovski | Original Music Composer |
| Sound | Alex Alcántara | Additional Sound Re-Recording Mixer |
| Costume & Make-Up | Paula Gámez | Special Effects Makeup Artist |
| Directing | Juan Galiñanes | Second Unit Director |
| Costume & Make-Up | Pedro Raúl de Diego | Special Effects Makeup Artist |
| Sound | David Machado | Sound |
| Sound | Kevi Aragunde | Foley Mixer |
| Sound | Diego S. Staub | Foley Mixer |
| Sound | Irma Areta | Sound Post Supervisor |
| Costume & Make-Up | Jesús García | Special Effects Makeup Artist |
| Costume & Make-Up | Raquel Álvarez | Special Effects Makeup Artist |
| Costume & Make-Up | Juan Olmo | Special Effects Makeup Artist |
| Sound | Miguel Barbosa | Foley Artist |
| Sound | Gabriel Gutiérrez | Sound Designer |
| Crew | Óscar Franco | Stunt Coordinator |
| Crew | Fany Veiga | Stunt Coordinator |
| Visual Effects | Roberto García | Digital Compositor |
| Visual Effects | Clara López | Visual Effects Coordinator |
| Visual Effects | Félix Bergés | Visual Effects Supervisor |
| Visual Effects | Elena González | Visual Effects Coordinator |
| Visual Effects | Antonio Miravalls | Visual Effects |
| Visual Effects | Quico Noizeux | Digital Compositor |
| Crew | José Carlos Extremadura | Stunts |
| Visual Effects | Cristian Martin | Digital Compositor |
| Visual Effects | José María Rincón | Visual Effects |
| Art | Astrid Mayor Ramis | Title Designer |
| Visual Effects | Berta Coderch | Visual Effects Producer |
| Crew | Gara Caballero | Visual Effects Editor |
| Visual Effects | Laura Pedro | Visual Effects Supervisor |
