'I am nobody of consequence,' the stranger replies.
'I am only here to give you this.
' He holds out his hand and in his open palm there nestles a small silver locket upon a chain.
'She asked me to return it to you, at the very end.
'A visitor calls with a gift and a message from the past.
In 1802 Thomas de Quincey, a young man from a comfortable middle-class background who would go on to become one of the most celebrated writers of his day, collapsed on Oxford Street and was discovered by a teenage prostitute who brought him back to her room and nursed him to health.
It was the beginning of a relationship that would introduce Thomas to a world just below the surface of London's polite society, where pleasure was a tradeable commodity and opium could seem the only relief from poverty.
Yet it is also a world where love might blossom, and goodness survive.
The lives of a street girl, an aspiring writer, and a freed slave cross and re-cross the slums of London in this novel about the birth of passion, the burden of addiction, and the consolations of literature.