The core of the episode focuses on the fall of , a high-security prison located five kilometers offshore that is designed to hold individuals whose Quirks pose a severe threat.

In of My Hero Academia Season 6, titled "Tartarus," the series shifts from the brutal frontlines of the Paranormal Liberation War to a devastating strategic blow against hero society. This episode marks a critical turning point, transitioning the story into its final stage with a massive prison break that releases thousands of dangerous villains back into the world. The Assault on Tartarus

, a new inmate introduced who strikes a deal with All For One to capture Izuku Midoriya in exchange for the Air Walk Quirk.

As the security fails, several notorious villains from previous seasons are freed, including: Muscular (Goto Imasuji) Moonfish

A key tactical move involves a synchronized Quirk-based EMP blast from both Shigaraki (outside) and All For One's original body (inside), which disables the prison’s complex electronic surveillance and locking systems.

(Kai Chisaki), who is shown in a desperate state seeking "Pops"

All For One orchestrates the raid from both the inside and outside. Using Shigaraki Tomura's body—which he now partially controls—he launches an aerial assault with High-End Nomu .

, who chooses to act independently rather than join All For One's army