When Mary receives a blank diary as a present, she thinks nothing of it. Until she opens the diary, and sees it's not blank after all. 1st January, Murder Lisa, Oxford. 1st February, Murder Jane, Birmingham. 1st March, Murder David, Cardiff. 1st April, Murder Mary, Cheltenham. Is this a sick joke? But... it's the end of January now. And a woman called Lisa was murdered in Oxford on 1st January. Could there really be a killer out there, planning to commit a new murder each month? And is the Mary due to be killed on 1st April her? The clock is ticking for Mary to uncover the truth, before she becomes the next victim on the killer's list...