Kika Markham

Poirot falls in love and finds a criminal intellect that pushes his own to the limit.

When a young woman is found brutally murdered on a train, the police call in a brilliant but unstable psychologist.

Kelly is put into Fitz's care after a lack of evidence. But after another murdered woman is found, Kelly is arrested and DCI Bilborough orders Fitz off the case. Fitz and DS Penhaligan collude to find out the truth.