When the Underworld spawns a supernatural plague that sweeps through London, Mio must use her family's ancient mystical sword to save the world from the forces of evil.

Ninjas are stealthy. They are disciplined. Ninjas trust no-one, and do not let anything deter them from completion of their mission. Teenage Kata has trained since childhood to live up to the exacting standards that Madame Chiyome sets for her "deadly flowers" - the girls who live a harsh, hungry life at her school for ninjas, and she is determined to succeed in her first mission as an assassin for hire. When it all goes wrong, she finds herself on...