England, the 19th Century. The almighty butler Sebastian of the Phantomhive House: the "evil nobles" that are contracted to perform Queen Victoria's "underground" work. His true form is that of a demon. According to his contract with his young Master Ciel, a proudly independent boy who faces his cursed fate head-on, he becomes Ciel's shadow and cleans up the incidents that occur in the underground society. One day, the two set out to investigate an outbreak of random killings in London on the Queen's orders. At the same time, the Grim Reaper Dispatch Society, which is burdened with the task of "collecting souls", has been troubled with a plague of "non-collectable souls". The Grim Reaper William T. Spears knocks his subordinate Grell Sutcliff, who does nothing but play hooky, over the head and leads the investigation with honour-student Grim Reaper Alan Humphries and his friend Eric Slingby. Demons, Grim Reapers, an incurable disease, a cursed past. The incident will entwine each of their destinies, as well as uncover the sad truth. Amongst all that, the curtain rises on the grand opera performance that the Aleistor Chamber is holding. Can death visit a Grim Reaper? Why can't the souls be collected? Alongside the sad and painful investigation is a Noir Fantasy in which the strings are pulled by the Black Butler.