Sinon is the loyal manservant of Cardinal Cardoza.
Sinon is Cardinal Cardoza's manservant, who meets Roger Ascham and Princess Elizabeth when they arrive in the city.
After the death of Cardinal Farnese, Cardoza realised that he was the intended victim of the poison, and instructed Sinon to kill chef Brunello and his wife, believing that they were the ones to try and murder him. Cardoza promised Sinon that he would absolve his murderous sins so that God would forgive him.
Sinon is killed by Roger Ascham when he attempts to kill him and Elizabeth as well.