From Viz:
Deep in the heart of 19th Century London, a young nobleman named Cain walks the shadowy cobblestone streets of the aristocratic society in which he was born. Forced to become an Earl upon the untimely death of his father, Cain assumes the role of head of the Hargreaves, a noble family with a dark past. With Riff, his faithful manservant, and Mary Weather, his 10-year-old half sister, Cain investigates the mysterious crimes that seem to follow him wherever he goes.

Through the looking glass into Camelot Garden, falls a boy named Ryu, whose purpose is to crush this weird, semi-malignant fantasy world. Oh yeah, and the below is a direct quote from the beginning of the story.

The Lady of Shallot
by Alfred Lord Tennyson
There she weaves by night and day
A magic web with colours gay.
She has heard a whisper say,
A curse is on her if she stay
To look down to Camelot.

But in her web she still delights
To weave the mirror’s magic sights:
A funeral, with plumes and lights
And music, came from Camelot.
“I am half-sick of shadows,” said
The Lady of Shalott.
“Tirra lirra, tirra lirra,”
Sang Sir Lancelot.
She left the web: she left the loom:
She looked down to Camelot.