JUST CAUSE 4 Gameplay Walkthrough Part 1 - INTRO (Full Game)

After the events of Just Cause 3, Rico Rodríguez is approached by Mira Morales, a native of Solís, who says that Rico's father, Miguel Rodríguez, was working on the Illapa Project, a weather weapon that Oscar Espinosa is using to control the people of Solís with.

After a failed attempt at deposing Espinosa and a run-in with his private army, the Black Hand, which is led by Gabriela Morales, Rico forms an army of his own with Mira, named the 'Army of Chaos', aimed at taking down Project Illapa and ending Espinosa's regime. Along the way, he meets up with Luis "Sargento", an eager commander of the Army of Chaos; Izzy, a hacker; Garland King, a filmmaker obsessed with filming stunts in Solís; and Javi Huerta, an archeologist wishing to uncover the history behind Solís and the Espinosa legacy. As Rico sets out to destroy the four prototype weather cores being tested in Solís, he also meets up with Lanza Morales, Mira's uncle and a scientist who worked on Project Illapa; César Pedrone, a former pilot turned conspiracy theorist; and Tom Sheldon, Rico's old handler at the Agency.

Soon, it is revealed that years ago, Miguel, together with Lanza, and Espinosa's father, Leon Espinosa, worked on the project with the aim of controlling the weather for the good of the people. However, Espinosa, convinced that his father was wasting his family's money on the project, took over after his father's sudden death and intended to weaponise Illapa's technology and research to sell to the highest bidder. Miguel, disgusted by the idea, left the project, but Espinosa used his control of Sebastiano Di Ravello in Medici and connections with the Agency to kill Miguel, before proceeding to imprison Lanza to force him to continue working on the project.

After Rico succeeds in destroying the four weather cores, and the Army takes over Espinosa's main base, Espinosa reveals that he has already created a perfected weather core that combines all four of the weather cores' abilities and is intending to sell it to the Agency for trillions of dollars. As Espinosa leaves in a jet and the weather core is poised to strike both the Army and the Black Hand at his main base, Rico, along with Gabriela, who turns against Espinosa after she realizes that he is sacrificing her army for his gain, gains control of the core, and drives it into Espinosa's jet, killing him and ending his regime.

As the Army of Chaos is celebrating their victory, Rico reveals that he and his father were just 'pawns in a larger game', and that everything 'always comes back to the Agency'. With that reasoning, Rico suggests attacking the Agency next, and both Sheldon and Mira agree to join him.