HERETIC turned spy Giordano Bruno is back in England and his creator SJ Parris is back on form with this riveting blend of espionage thriller and murder mystery.

The maverick Italian philosopher is again working for real-life Elizabethan spymaster Sir Francis Walsingham on a mission that puts him in deadly danger.

The setting is rich in atmosphere and possibilities – the long rivalry between Queen Elizabeth and Mary Queen of Scots, who despite imprisonment continues to plot against the English monarch.

Mary gathers Catholic conspirators like moths to a flame, and Walsingham is determined to prove she is a willing participant in the plots rather than simply inspiring them.

Enter Bruno, returning in secret from France with letters that outline the latest plans to assassinate Elizabeth.

Walsingham's daughter asks Bruno to investigate the brutal death of her companion Clara, and he soon discovers she was a spy too, sent undercover with the conspirators by Walsinham. Her inexperience may have caused her death.

Amidst acrimony from father and daughter, Bruno follows Clara's path, posing as a Jesuit priest who has been sent from Europe to help the conspirators kill Elizabeth.

From this compelling set-up, Parris winds up the tension as Bruno seeks both evidence against the plotters and the truth about Clara's death.

Bruno arrived on the scene several years ago amongst a pack of Tudor investigators created in the wake of CJ Ransom's mega-selling books about Tudor lawyer Shardlake.

Bruno was one of the most interesting of the new characters, and I enjoyed the first few books but gave up after I found it a grind reading through the fourth, Treachery. I skipped number five, Conspiracy, which took Bruno to Paris.

I'm glad I decided to return for Bruno's sixth outing Execution, because it's one of Parris's best novels, making the most of its setting amidst the intrigues and terror of Elizabethan England.

David Knights