The role of Lucius Vitellius in the events leading to the death of Valeria Messallina, the third wife of the emperor Claudius, in autumn AD48 is re-examined. It is argued that the freedman Narcissus delayed his action against Messallina for her dangerous affair with Gaius Silius until he could be sure of the tacit support of Vitellius, where Vitellius had been hoping for a practical opportunity to strike against Messallina ever since she had forced him to play a key part in the trial of his friend Valerius Asiaticus in late AD47.