Lying injured on a bed, Kirika awakens to see Mireille aiming a gun at her. Inviting her to take the shot, Kirika thanks Mireille for putting up with her. Will Mireille kill her partner? And how did this situation come about in the first place?
Balsan, the leader of a revolutionary movement, has been murdered. The remaining revolutionaries have captured an old man, believed to be the one who hired the assassins. When his allies are shot in front of him, the man tells the revolutionaries that the assassin he hired was Noir, the highest ranked of all assassins- but that is all he knows.
Kirika was the one who killed Balsan, but unfortunately, she did not make a clean getaway, and was shot herself. Worse still, to make contact with the chopper that will take them home, Mireille and Kirika will have to cross the desert on foot- and in Kirika’s current condition, they will never make it time.
Meanwhile, the revolutionaries discuss going after Noir, who they believe to be a single man. Despite Noir’s fearsome reputation, they are desperate for revenge, and decide to follow Mireille and Kirika’s trail.
Unable to drive any further in her car, Mireille stops at a village on the edge of desert. The two women rest in an old building, where Kirika confesses that she dropped her ID card at the revolutionary base. This is not good news, but Mireille has other concerns. She realises that, without Kirika, she could still make it to the pick-up point on time. Raising her gun, she prepares to shoot Kirika, and as Kirika urges her to hurry up, Mireille raises her gun, and a shot is fired…
…As it turns out, Mireille has only shot the pillow beside Kirika. Putting the gun away, she laughs off the idea that she was thinking of killing her partner- not because she cares about Kirika, she claims, but because Kirika is her link to the mysterious Soldats. Only when the all the mysteries are solved will she kill Kirika.
Mireille heads into the village to buy some supplies, little realising that the revolutionaries have tracked them down. Following a trail of blood from Mireille’s car, they find Kirika, and are amazed to discover that the assassin is merely a girl. Believing her to be an associate of Noir, they take Kirika away.
Seeing the revolutionaries’ truck in town, Mireille races back to Kirika, but, outnumbered and outgunned, all she can do is watch as Kirika is thrown into the truck and taken away. Still, Mireille isn’t about to give up on her partner so easily, and follows the revolutionaries back to their base.
Back at the base, a barely conscious Kirika is being questioned about her connections to Noir. When one of the revolutionaries returns her ID card, the questioner realises it is precious to her, and takes great in causing Kirika pain as she attempts to pick it up. He is not about to give her the release of death, but he is desperate to inflict pain in retribution for Balsan’s murder.
Having arrived at the base, Mireille proceeds to take out the guards. Making her way down to Kirika’s cell, she explains one important fact to the doomed revolutionaries- the codename Noir is not one person, but two. A small mistake, perhaps, but the last one they will ever make.
The few revolutionaries remaining in Kirika’s cell are about to leave and hunt down the intruder, that is, until Kirika finally seems ready to talk. As she begins to recite “Noir, It is the name of an ancient fate…”, the revolutionaries turn back to her. Summoning the last of her strength, Kirika rises up and cuts her torturer with her ID card. Shocked and distracted, the revolutionaries do not see Mireille, who shoots them all before they have time to react.
With Kirika rescued, the two women can finally make it out into the desert. Sending up a flare, they wait to be picked up. As they stand together, Mireille remarks that unlike lovers, who are connected by a red string, the two assassins are joined by a thread of a far darker and more sinister colour- black.