Murder, spies, mathematics and music it s all in a day s work for Phryne Fisher in her 20th adventure! An orchestral conductor has been found dead and Detective Inspector Jack Robinson needs the delightfully incisive and sophisticated Miss Fisher s assistance to enter a world in which he is at sea. Hugh Tregennis, t much liked by anyone, has been murdered in a most flamboyant mode by a killer with a point to prove. But how many killers is Phryne really stalking? At the same time, the dark curls, disdainful air and the lavender eyes of mathematician and code-breaker Rupert Sheffield are taking Melbourne by storm. They ve certainly taken the heart of Phryne s old friend from the trenches of WW1, John Wilson. Phryne recognises Sheffield as a man who attracts danger and is determined to protect John from harm. With Mendelssohn s Elijah, memories of the Great War, and the science of deduction ringing her head, Phryne s past must also play it s part as MI6 becomes involved in the tangled web of murders.