William Fletcher (The Haunting of Villa Diodati)

Fletcher was Lord Byron's valet, (PROSE: The Book of the War, TV: The Haunting of Villa Diodati) an agent for the Grand Families, and a member of the Shelley Cabal.

In 1809, Fletcher, Byron, and Hobhouse were tasked by the Star Chamber to investigate rumours of the Mal'akh in the court of Ali Tebelen. In September, Fletcher and Hobhouse orchestrated the ritual that resulted in the Maltese incident. (PROSE: The Book of the War)

In June 1816, John Pilodori chose Fletcher as his second for his pistol duel with Ryan Sinclair. (TV: The Haunting of Villa Diodati)

In the first years of Byron's marriage to Annabella, Fletcher often had to intervene to stop him from attacking her.

In 1822, Fletcher and other members of the Shelley Cabal confronted a group of Mal'akh near Massa. Fletcher and Byron were separated from the others, whose bodies later washed ashore.

Two years later, Fletcher helped "stage manage" Byron's death to cover Byron's acceptance into Faction Paradox and departure for the Eleven-Day Empire. (PROSE: The Book of the War)

Behind the scenes
In the real world, Fletcher's first name was William.