On his way back to the Black Order headquarters from Mater, Allen meets a boy named Jean. Jean and his friends have organized a patrol to search for Akuma within the town. Allen warns the boy that this is dangerous, but Jean won't listen.

Allen's past is revealed as he confronts the Earl of the millennium, who wants to kill Jean for causing problems with his patrol and calling the Earl "a bad guy".

While searching for an Innocence in Rome, Kanda encounters a mysterious swordsman named Victorio, whose power is unbelievably strong. When Kanda hasn't returned after a while, Komui asks Allen and Lenalee to go to Rome to investigate why Kanda is taking so long, thus they learn the history of Victorio and the Princess, whom he vowed to always fight for.

Allen, Lenalee and Kanda find themselves in a predicament when they battle Victorio. How can they stop someone who apparently cannot die from shear wounds?

Allen crosses paths with Yeeger - the oldest general in the Black Order. After a fierce battle, a generous meal, and a heart-rending story of loss, the exorcist’s spirit is renewed.

After General Yeegar's tragic death, Allen, Lenalee, Lavi and Krory are separated into two groups and sent to look for General Cross and guard him from the enemy. During this time, Allen tells Lenalee his bitter memories of Cross and the tragedy of a good friend.

The Millennium Earl is seen bouncing about cheerfully, answering several phone calls and confirming business deals. Allen and Lenalee arrive at Liverpool to meet Mother, who took care of Allen during his training years with General Cross, to ask her about his master's whereabouts. Both exorcists soon discover akuma in the area and a possible conspiracy at a local hospital.

While Allen comforts Lisa as she mourns her sweetheart's death, Lenalee investigates the cause of why there is a large quantity of akuma in the area, thus revealing the work of a Broker, who sells souls to the Millennium Earl. There are two suspects, the chief doctor, and a young money-hungry one. Working undercover as a nurse, Lenalee is determined to find out who.

As she is on her way to reunite with Allen, Lenalee agrees to accompany Gozu to the next town. However, in the midst of the forest, they meet a group of stranded villagers, running away from their home because of wolf attacks. The wolf attacks are revealed to be the work of Akuma and Lenalee receives help from Suman Dark, an exorcist and long time friend, who is searching for General Zokalo.

Stranded on a rain-drenched night, Allen and his friends are lured into a trap by a black cat, but a growling stomach may prove to be their saving grace.

Seeking a guide to lead them through a treacherous mountain pass, Allen and Krory stumble into a devious trap. Soon they will be visited by visions of the past.

Allen and his friends resume their search for General Cross. After arriving at his last known location, they receive some terribly disheartening news.