|Episode 10 «|| 別離 / 心の闇 / かげがえのないもの
Parting / Darkness of the Heart / Irreplaceable Thing
|» Episode 12|
Rakka takes the young feather Dai back to the Abandoned Factory for his extended visit, and meets the other haibane there. Midori tells Rakka that Reki hazarded Hyouko in the past. Washi tells Rakka that Reki doesn't have much time left, and Rakka decides to help Reki to overcome her sin-boundness and reach her Day of Flight.
Nemu catches a cold, and Rakka volunteers to go into town and tell the library about it, where she meets Sumika. After that, she meets Reki, and they walk back together. They part, and Rakka runs away and cries, because she feels so sorry for Reki. Reki goes to her studio to finish something important.
For a more detailed summary, read about episode 11 on Sekai no Hajimari.