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.

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.