Durarara!! Episode 17

"Tell me, Mikado. What do you think a truly unusual life would be like? Something really unique. It'd be the kind of life where every single day, nothing new ever happened. Nothing changed. That kind of a life is truly unusual."

- Anri Sonohara

"Perpetual Shifts and Changes" is the seventeenth episode of the Durarara!! anime and the eighteenth episode overall.

Synopsis
In South Ikebukuro Park, Shizuo Heiwajima is fighting the Saika Army as Celty Sturluson watches in awe. The moment that Anri Sonohara pulls Saika from her arm in another part of the city, all of the people in the park stop fighting and turn in her direction. As Celty leaves the park to investigate, she tosses Shizuo a pair of gloves made from her shadows that are strong enough to withstand the blades he is fighting. The cuts covering his body have no effect on him, his lack of fear keeping the Saika Army's thoughts from entering his mind. To himself, Shizuo admits to feeling afraid of himself losing control and decides to give the fight his all.

Anri has Haruna Niekawa cornered and disarmed and asks her to order the children of her Saika to stop slashing people across the city. She pierces Haruna with the tip of Saika, forcing Haruna to listen to the blade's overwhelming words of love. Anri herself is only able to bear Saika's voice because of her own inability to love. Due to closing off her heart when her father abused her and her mother committed murder-suicide, she leeches off of others to compensate for the qualities she lacks, becoming Saika's parasite. Haruna picks up her knife and cuts Anri several times, but Anri only accepts the injuries as consequence for what she is about to do: in order to protect the peace in her life, she takes over Haruna's mind. Haruna and her army awaken from their possessed state.

As the slashers around him awaken in confusion, Shizuo is delighted to discover that no one was killed in the fight, and he was finally able to control his body. Celty catches up to Anri, and Nasujima tries to take Anri away. Anri explains that she has already repaid him for the times he looked out for her at school by protecting him in secret, and Celty recognizes him as a man she was hired to chase down months earlier. Anri promises that she won't hurt him, because she isn't like Haruna, and Nasujima runs away.

Out of luck and desperate for money to pay off his debts to the Awakusu-kai, Nasujima runs into Shizuo and demands his money, realizing too late who he is threatening. The van gang find Nasujima shortly after. Unable to remember anything, he is left bound on the side of the road.

The following day, the van gang are riding their van around the city, Saburo upset about the replacement door Walker has found and Kyouhei warning the group that the car now stands out too much for them to get up to trouble in it. They note the large numbers of police in the city center apprehending Yellow Scarves members as they simultaneously receive emails from the Dollars admin seeking information on the slasher.

Mikado Ryuugamine visits Anri in Raira General Hospital, and Anri excitedly tells him about the people who came to her aid the night before. However, upon taking control of the hundreds of Saika followers Haruna had created, she had absorbed their memories and learned about Izaya Orihara, who stands in the shadows and pulls the strings. She decides to keep him from hurting Mikado and Masaomi while at the same time keeping Saika a secret from them.

In Shinjuku, Izaya reveals to Namie Yagiri the strings he had pulled and how few of the events leading up to the previous night had been coincidences. While a few surprises had occurred, everything is going the way he had planned.

In a warehouse in another part of the city, Masaomi commands the full respect of the Yellow Scarves, who beg him to act. Thinking of Anri in the hospital and the disruption of his peaceful, normal high school life, he dons a yellow scarf and informs the gang that they are going after the slashers, and if they have to, the Dollars as well.

Character Appearances
In order of appearance, excluding the opening song:

Cultural References

 * When Walker and Erika are discussing Dengeki Bunko series in the back of the van, Walker mentions the series Kino's Journey.
 * Walker is later reading a news article on Yohoo! Japan, a clear parody of the web services company Yahoo!
 * As in episode 11, Walker's ringtone is Japanese voice actor Daisuke Ono saying "Bocchan, meeru de gozaimasu" which translates as "Young master, you've got mail." Ono voices Sebastian Michaelis in Black Butler and is also the voice actor for Shizuo Heiwajima.
 * Erika's ringtone is again the voice of character Ai Enma from the anime Hell Girl saying her catchphrase "Ippen shinde miru?" which roughly translates to "Do you want to trying dying this once?"

Quotes
Shizuo: "There's no way I'm going down in front of the people who love me."

Celty (to Anri): "If you still have your doubts, then I suggest you stop questioning yourself, and instead use that power you have to better this town."

Izaya (about Anri): "She had obtained a power, a power that allowed her to control a hundred Saikas and bend them to her will. It was no small burden for her to bear, but at the same time, it was a load she was glad to carry. She'd always felt somewhat adrift before, but now, with the fate of others weighing in her hands, she finally felt grounded in reality."