Cases of mass robbery are believed to be by a culprit who was responsible for murdering Eisuke Tomari. Shinnosuke is pumped up to solve the case alone. Meanwhile, Brain appears before Go and offers an alliance.

Due to Mach’s intervention, Shinnosuke could not apprehend the murderer of his father. Has Mach become the enemy? In addition, Shinnosuke is regretful about prioritizing his need for answers over saving lives and lets Chase know.

In contrast, Kiriko, having seen Go's betrayal, is starting to have trouble with solving the case and is getting hasty. The reason: this change in Go is no doubt the work of Roidmude 001 and this case is deeply connected to him as well. Brain is trying to get rid of anyone with any relation to the bank robbery from 12 years ago and Maruya (Negishi's former accomplice) testifies feeling something that could very well be a "thick air" event.

Meanwhile, the recovery of Protodrive's memories that Chase had requested to Kiriko is complete. An unthinkable truth was hidden there.

Mitsuhide Nira, who has been revealed to be the murderer of Eisuke Tomari, takes steps with Brain to hide away the evidence from 12 years ago. Moreover, they hold a press conference, falsely accusing the Special Investigation Unit of colluding with the Roidmudes, landing them in jail and Shinnosuke as the public's most wanted criminal. Shinnosuke must find a way to free the Unit and expose Nira of his crimes.

Nira put the Special Investigations Unit in siege to lure Shinnosuke into a trap. He intends, after framing Shinnosuke for the whole incident, to kill him and make it appear as if it was self-defense with the same gun that killed Shinnosuke’s father, with the other Riders fairing no worse, with Go fighting Heart wanting Banno's tablet, and Chase unable to save a poisoned Yukari with Mad Doctor.