A group of dangerous incarcerated super-villains are recruited by the shady government agency Task Force X, colloquially known as the Suicide Squad, for a black-ops mission on the remote, enemy-infused island of Corto Maltese. Under the ruthless supervision of Amanda Waller, the eclectic team is armed and dropped into the thick of action. Among them are Harley Quinn, a crazed yet skilled former psychiatrist; Bloodsport, a skilled mercenary with a lethal aim; Peacemaker, a jingoistic patriot willing to kill for peace; Ratcatcher 2, who controls rats; King Shark, a humanoid shark with immense strength; and others equally lethal. Each member has a small explosive device implanted in their head to ensure compliance. Their goal is to destroy all traces of Project Starfish.

Upon arrival on the island, the squad faces immediate resistance from the Corto Maltese military and quickly learns the complexities of the mission. While navigating a landscape of political turmoil after a recent regime change, they must infiltrate Jotunheim, a Nazi-era prison and laboratory that holds a secretive experiment. As they battle their way through the opposition, the team slowly learns about each other and what they are fighting for. Secrets start to unravel within the team, alliances are tested, and the true nature of Project Starfish becomes clearer, presenting the squad with challenges that question their morality and their willingness to work together for a shot at redemption.