Allen and Lenalee head to Rome on an assignment, where Kanda has been for an entire week without contact. They must investigate the existence of a thousand year old swordsman because it is highly likely he is being kept alive by Innocence.
Though upon reaching the city, they soon learn the daughter of the wealthy Sardini Family has been kidnapped, and that the swordsman may somehow be involved.
One thousand years ago in Rome, the King had a beautiful daughter named Sandra. She was so beautiful that men arrived from around the world to ask for her hand in marriage. Sandra eventually proclaimed she will only marry the strongest man in the world, having her family's swordsman Victorio test their strength. No one had ever beaten the swordsman and it is said he still lives and fights despite Princess Sandra having died all those years ago. Kanda has now become Victorio's opponent.
At the Black Order, Allen finds out from Komui that they have not heard from Kanda, who is out on an assignment in Rome, for an entire week. Since there are a lot of Akuma in the area, Komui decides to send Allen there.
As Allen departs, he is surprised to see Lenalee boarding the boat. He quickly notices she is still angry with him over what happened when they fought Road. When they reach the train station, Allen apologises profusely to Lenalee, who berates him for thinking everything is up to him because of his ability to see the Akuma's souls. She goes on to explain she feels insulted that he will not let her fight by his side. With that, Allen thanks her for saving his life and Lenalee boards the train, leaving him to wonder if she had forgiven him or not.
While on the train Allen and Lenalee discuss the details of their mission, which involves the investigation of a Roman swordsman who lived a thousand years ago and is said to still be alive. They wonder if it is possible he is an accommodator, but are unsure if Innocence even has the ability to keep someone alive. They also find that Akuma have been appearing around the arena where the swordsman is said to have been seen, but none of them had ever gotten out, which had ultimately lead Komui to believe Innocence is involved. Meanwhile Kanda, who is at the arena with his finder Pedro, destroys a group of level 1 Akuma.
When Allen and Lenalee arrive at the city, they find the area filled with a gathering of bounty hunters called out by the Sardini Family, to help them find their missing daughter. Afterwards, Allen and Lenalee decide to go to the Sardini Family party to try to gather more information. They find out that the kidnapped girl, Claudia, is engaged to a Viscount named Paletti, who has just announced the reward will be one tenth of the Sardini fortune, which angers Mr. Sardini since such a thing had not been discussed.
A short time later, Allen and Lenalee get into the Sardini Family home through a window to speak with Mr. Sardini and reveal they are with the Black Order, which he seems to know about. He tells them about Claudia and how she had continuously been approached by a swordsman who always gave her reports about him being unable to find the strongest man. He did not believe her, but Claudia was then kidnapped the moment she was engaged to the Viscount.
At that moment, Paletti arrives and tells them if Claudia went through with their marriage the Sardini Family would be recognised as being part of upper class society. The two argue over how the situation is being handled, which all boils down to money, causing Allen to berate them for only being concerned with money, status and fortune. With that, he and Lenalee take their leave.
Allen and Lenalee head to an Inn, downhearted about not being able to learn anything from Mr. Sardini or the Viscount. However, Lenalee is sceptical about idea that Claudia simply ran away, leading her to believe the swordsman really does exist.
The next day the bounty hunters go to the arena, where they are bombarded with bullets from level 1 Akuma. Allen and Lenalee join the fray and begin to fight them off, trying their best to protect the bounty hunters. Meanwhile, outside the arena, it is revealed the bounty has been raised to one fifth of the Sardini Family fortune.
Inside the arena, Victorio appears and easily takes down the level 1 Akuma, as well as the remaining bounty hunters. Allen readies himself to fight Victorio, but Kanda stops him, claiming that he is his opponent. As Kanda begins to fight Victorio, Pedro approaches Lenalee. He tells her and Allen Victorio's sword contains Innocence, which has been keeping him alive for a thousand years. He also tells them that Kanda and Victorio had been fighting for three days straight before the Akuma had interrupted them, causing Victorio to disappear. It is noted the two did not use their anti-Akuma weapons, possibly due to their pride as swordsmen.
Kanda manages to slash Victorio in the neck, however his wound heals immediately afterwards and he stabs Kanda in the abdomen, causing him to bleed out.