Herurisu! is the 43rd chapter of the Bungou Stray Dogs manga.
Atsushi and Kyouka head off to Uzumaki Cafe to discuss a case. They are met by an annoyed Lucy Maud Montgomery. Lucy hands them a dispatch regarding the murder of Kyouka's parents. It turns out there is one page missing from the booklet, and Atsushi and Kyouka head off to a dock to find the missing page. Atsushi and Kyouka split up and Atsushi then meets Lucy. She taunts the missing page to Atsushi. Lucy gets annoyed and yells at Atsushi for not saving her from Moby Dick as he promised. Lucy then throws the page into the ocean. Atsushi immediately jumps into the water but is trapped by discarded anchor chains. Lucy then sees that Atsushi will drown and jumps in after him. She then uses her ability to save the both of them. Atsushi explains that he did try to search for her after the war. They then go back to the surface and meet up with Kyouka. The three go back to the cafe and read the report. Three years ago, Kyouka's father was originally a secret agent for the government. But after a certain incident, he resigned. Kyouka's father along with Kyouka's mother; the wielder of Demon Snow, they took care of multiple assassinations. But one day, Kyouka's father tried to murder Kyouka but it was the doing of an ability user who had the ability to manipulate bodies. Demon Snow then murders him. Kyouka's mother, also is under the affect of the ability. She realizes that it is body manipulation through blood. In the last moment, she tells Demon Snow to protect Kyouka. Demon Snow then murders Kyouka's mother. It turns out that there is a way to transfer abilities to a blood relative. It appeared that an ability user who could manipulate shadows taught Kyouka's mother. But because during the attack the transfer was so sudden, Kyouka could not fully control her ability.