Mix Cellini (which he pronounces with an 'S' rather than a 'C') is superstitious about the number 13. In the musty old house where he is the lodger, there are thirteen steps down to the landing below his rooms, which he keeps spick and span. His elderly landlady, Gwendolen Chawcer, was born in St Blaise House, and lives her life almost exclusively through her library of books, so cannot see the decay and neglect around her.

The Notting Hill neighbourhood has changed radically over the last fifty years, and 10 Rillington Place, where the notorious John Christie committed a series of foul murders, has been torn down. Mix is obsessed with the life of Christie and his small library is composed entirely of books on the subject. He has also developed a passion for a beautiful model who lives nearby - a woman who would not look at him twice.

Both landlady and lodger inhabit weird worlds of their own. But reality intrudes into Mix's life, leading to long pent-up violence.