Promises Written in Water
Shinya looks out at the view
Episode Information
Kanji 水に書いた約束
Rōmaji Mizu ni kai ta Yakusoku
Air date February 21, 2013
Opening Out of Control
Ending All Alone With You
Episode Guide
Heart of Iron
Transparent Shadow

Promises Written in Water is the eighteenth episode of Psycho-Pass.


Kogami is taken off the case by Kasei, who has deemed the Enforcer a threat. Kogami speculates that the Chief may have wanted to use Makishima for something when they were on transit to the Ministry of Welfare's building. Tsunemori forces Kogami to promise that he'll be a detective no matter what. Ginoza tries to get Kogami on a different case by sending him to Division 2. However, Kasei finds out and forces Ginoza's Dominator mode from the Paralyzer to the Eliminator and orders him to kill Kogami. Fortunately, Tsunemori fires at Kogami first, knocking him out with her Paralyzer. She tells Ginoza that his Dominator is probably broken. Kogami wakes up to find Tsunemori by his bedside. He goes to Karanomori and asks her for the helmet and she tells him to go ahead. Kogami has a short conversation with Masaoka, who gives Kogami the keys to his safehouse and tells Kogami that he should at least write Tsunemori a letter. Kogami uses the helmet to escape the MWPSB and go to the safehouse. He takes some parts and uses it to construct a revolver. Meanwhile, Tsunemori finds the letter and reads it. Tears fall from her face when she finishes reading it and calls Kogami an idiot.

Kogami's Letter

I'm sorry. I couldn't keep my promise. I wanted to go into a line of work where I could protect people. That's why I became a detective. But Makishima changed everything. That man will continue to kill people. And yet, the law can't judge him. As long as I'm a detective, I can't touch him. This case made me aware that the law can't protect people. In that case, my only option is to step outside the law. Akane Tsunemori... There is no doubt that your way of living is correct. Don't lose sight of that just because I betrayed you. I selfishly chose a different path solely in order to get my own way. I'm aware that this is a mistake. But I know I can only come to terms with my old self by taking the wrong path. I won't say forgive me. The next time we meet, you'll be in a position to judge me. When that time comes, fulfill your duty with no mercy. Don't turn your back on your beliefs. Although it was only for a short time, I feel fortunate that I was able to work under you. Thank you.