- Written by Junko KoumuraDirected by Ryuta Tasaki
Medic discusses with Heart the event of Go Shijima joining forces with them. While they did know that it was Brain's deed all along, but Heart somehow knows who is the true mastermind. At the same time, Brain gives Itsurou the list of eyewitnesses from the robbery that happened during 12 years ago.
The day after Go betrays his team, Shinnosuke visits Chase, thanking him for opening his eyes to protect the people rather than seeking vengeance. Chase asks Shinnosuke about the importance of family members which Shinnosuke answers. With Kiriko unable to contact Go, she calls Chase and Shinnosuke and tells them that Maruya seems to have gained some part of his memory. Maruya reveals to the Special Investigation Unit that during the robbery, he, Itsurou and the hostages did feel the Heavy Acceleration effect, confirming a Roidmude activity at that time. As Chase looks into the snowflake scar at the back of Maruya's ear, he revealed a vital clue: Roidmude 001 has the ability to create ice threads that allows him to rewrite human memories, leaving behind said scar. Meaning that Go's turncoat and Maruya's inability to remember his past was all to conceal the event from 12 years ago. But Yukari had no scar, meaning that she may remember the event. While Chase, Kiriko and Shinnosuke exit the office, Jun orders Rinna and Kyu to protect Maruya.
Kiriko visits Yukari at the hospital and tries to force her to remember what happened in her past but she gets traumatized. Shinnosuke arrives and tells Kiriko to stop, realizing that 001's case had made them leave behind the police's number one priority: to protect the civilians. Chase calls Go as they get into a fight again, but after Chase wins, he looks behind Go's ear, revealing that Go has also fallen victim to 001's memory manipulation. At the Unit's office, Nira once again tries to bring Maruya away from them so that the First Division can grant him protection instead but thanks to Colorful Commercial, he witnesses a lot of Maruya's clones and gets confused.
At the hospital's cafeteria, Yukari's mother reveals to Kiriko and Shinnosuke that Eisuke had protected her daughter and husband 12 years ago in that robbery and with Shinnosuke saving her yesterday, she can't help but to express her thanks to him. At Yukari's ward, Itsurou reveals himself and tries to kill her as Open Roidmude. Shinnosuke races himself to her ward and quickly saves her from Open as they escape. Once outside the hospital, Open tries to attack them again and as he fires at Yukari, Shinnosuke quickly shields her, triggering some of her past memory. Kamen Rider Chaser joins the battle, where both Riders performs Full Throttle finishers that separates Itsurou and kills Roidmude 067, ending his life.
After arresting Itsurou, Shinnosuke realizes that he also became a victim of the brainwashing, evidenced by the snowflake scar behind his ear. Chase wanted to tell Kiriko what happened to Go but knowing how much she would be affected, he lies that Go has not fallen for 001's trance. Kiriko quickly remembers and gives him the fixed Shift Speed Prototype Car. Yukari thanks Shinnosuke and reveals that Roidmude 001 was indeed present at the robbery. After inserting the Shift Car, Chase regains his memories, but due to overload, it displays some of his final moments before being brainwashed by the first three Roidmudes, 001, 002 (Heart) and 003 (Brain). Much to Shinnosuke's surprise, 001 was revealed to be the Secretary of National Defense Bureau, Soichi Makage.
- Air Jousting: Gou and Chase once again end their fight with a Rider Kick variation on this trope. Chase wins.
- Big "NO!": Unable to process the Mayura clone-fest, Nira turns towards the camera and lets out a big one in English.
- Flash Back Echo: Type 5. When Drive shields Yukari with his own body from Open's attack, she flashes back to how his father did the same for her 12 years ago.
- Gory Discretion Shot: The camera pans out just when we would be shown the process with the Roidmude Executive used to brainwash Proto-Drive!Chase to their side. From his perspective. While being strapped to an operating table.
- Hologram:The SCU once again fools Nira with Colorful Commercial, this time by creating multiple clones of Mayura when Nira came to take him into 1st Division's custody.
- Honor Before Reason: Shinnosuke stops Kiriko from forcibly questioning Yukari about the robbery from 12 years ago because of this - They first priority is to protect the citizens, finding 001 comes after that.
- Identical Stranger: Mockingly invoked by Kyuu to Nira when a dozen of Mayuras comes into the SCU's room.Kyuu: Well, y'know how they say everyone has an exact double out there, somewhere? Well, looks like some of the doubles have doubles of their own!
- Internal Reveal: The heroes finally learn that Soichi Mikage, the Secretary of Defense, is actually Roidmude 001.
- Poor Communication Kills: At the start of the episode, Shinnosuke apologizes to Chase for his behavior. He explains to him that humans are prone to drastic emotions with matters concerning their families. When Kiriko inquires Chase about Gou, whether he was brainwashed or not, he lies, because he thinks that it's better for her not to know based on what Shinnosuke told him.
- Then Let Me Be Evil: After arresting Neigishi, Shinnosuke asks why he returned to crime, despite Mayura looking up to him as a big brother-type figure. He says that, since he's a Cop Killer, he's never going to have a normal life. So, he may as well show the world how evil he can get. But 001's mark behind his ear puts his motive into question.
- You Didn't Ask: Chase says this when Rinna yells at him for not telling about 001's memory-wiping powers before.
- The Roidmude Count: 59The Answer: Yukari and Chase can.
