Atsushi Nakajima and Lucy Maud Montgomery vs. Nathaniel Hawthorne

Atsushi Nakajima and Lucy Maud Montgomery vs. Nathaniel Hawthorne is a skirmish fought between Armed Detective Agency member Atsushi Nakajima and ally Lucy Maud Montgomery against assassin Nathaniel Hawthorne acting on orders of Fyodor Dostoevsky.

It happened outside the airborne Sky Casino and later Anne's_Room as transported by Lucy. The battle occurred subsequently after the casino manager and Decay of the Angel member Sigma engaged the Hunting Dogs vice commander Teruko Okura on the hunt for the wanted Agency and Decay terrorists.

Prologue
When Atsushi manages to have Sigma cooperate with them, Hawthorne hovers before them and prepares to attack with his blood bullet. Ango Sakaguchi warns Atsushi that he might attack him and save Sigma—his fellow terrorist—along the process, but Hawthorne ends up shooting Sigma, much to all their surprise.

Battle
Atsushi holds on to their remaining lead, but Hawthorne also shoots him on the forehead. He quickly regains consciousness and grabs on to Sigma once more, but the latter ultimately gives up and lets himself fall off the casino. With Atsushi hanging on a ledge using his tiger tail, Ango directs Lucy to his direction. Against all odds, she immediately jumps off the casino to get near Atsushi and transports themselves to Anne's_Room.

The two successfully and safely land in the dimension. As Atsushi thanks Lucy, he swiftly shields her from an incoming blood bullet, which grazes her arm. Hawthorne also appears before them inside the dimension, with which Atsushi notices a thin thread of blood on him that must have allowed Hawthorne to enter when Atsushi was transported inside. Though Atsushi finds it bothersome, Anne quickly captures Hawthorne, with Lucy firmly asserting his defeat.

Hawthorne showers a barrage of blood bullets at Anne, but to no avail; Lucy explains that Anne cannot be harmed whilst inside the dimension. Various puppet arms soon emerge and drag Hawthorne into the secret room, imprisoning him.

Aftermath
Lucy turns glad that they managed to capture Hawthorne and win, but Ango tells otherwise, since they have suffered a great loss: Sigma is apparently gone, they are unable to track the page's location, and they are found by the Hunting Dogs rescuing a "fellow" terrorist. In other words, he fears that they merely ended up heightening their charges and have played right into Fyodor's hand that not even Osamu Dazai might have not seen through.