Canaan, a covert agent with the power of synesthesia (the ability to combine senses), arrives in China just in time to save her friend, the young photojournalist Maria Osawa, from a deadly attack by the terrorist organization known as Snake. But Canaan has tenuous ties to various Snake operatives, which places Maria in peril.

As Minorikawa realizes Maria has a connection to the mysterious assassin Canaan, they are attacked in downtown Shanghai by a mysterious old man and his young accomplice. But as they are on the run from the dangerous duo, Canaan comes to their rescue, provoking a dangerous revenge.

Rescued by her "sister" Liang-Chi, and now taking her place of power as the leader of the terrorist organization Snake, Alphard sets a trap for Canaan, luring her out into the open at a glamorous state dinner. Once there, Alphard reveals she and Canaan have more in common than Canaan ever let on.

Minorikawa and Maria receive an invitation to attend the anti-terrorism conference, but it's only a ruse by Alphard to lure Canaan to the summit. Once there, Liang-Chi and Alphard launch their attack, sealing the world's key diplomats in an office chamber, infecting them with the Ua virus--and causing Canaan to rescue Maria, putting her own life in danger.

As Liang-Chi's subversive plan takes a deadly toll on the group, Canaan and her companions struggle to escape before more lives are lost. Meanwhile, Natsume and Alphard reveal they have a common connection to the Ua virus and the mysterious Factory. But when Liang-Chi discovers she cannot reclaim Alphard's love, she makes a tragic decision.

Alphard kidnaps both Maria and Yun Yun in an attempt to trap Canaan into a deadly confrontation. As both girls hurtle toward certain death aboard a runaway train rigged with explosives, Canaan risks a daring rescue. But when she is confronted by Alphard, she discovers a terrible secret that threatens her very soul.