The Fantastical Mystery Of Ritterhouse Fay

Fay arrives in London from nowhere, moves into flat 6 at number 13, feels she has "come home" -- but the other tenants feel very differently:

RITA IN FLAT 1: "If only she had known then, known for certain, known what Fay was about and acted upon it. Tripped her on the stairs and frightened her away, dropped a flower pot on her head, cut her lying throat! Anything. ANYTHING -- before it was too late!"

MRS TAYLOR IN FLAT 3: "Pass on witch," mutters Taylor, as it takes one to know one, "pass on witchy-witch-witch."

WHO IS FAY? WHAT DOES SHE WANT? WHAT IS THAT ODD VOICE SHE HEARS? --- THAT SLANGY, TAUNTING, MYSTERIOUS VOICE?!