- "Ah. There you are!"
- ―Kaylock during the gang war, 1868.[src]
Kaylock was born in Whitechapel, and knew every nook and cranny of the area, which gave him the strategical advantage against his enemies. Sometime prior to 1868, Kaylock was handpicked by Grand Master Crawford Starrick to be one of the Blighters' leaders in London, making him the gang leader of Whitechapel. He was trained by Maxwell Roth, and quickly became known for being cunning and charismatic, preferring to toy with his enemies before finishing them off.
When Agnes MacBean was found to be impersonating her father and operating his train, Starrick impounded the vehicle. He then handed the train, along with Agnes herself, to Kaylock, to be used as a mobile headquarters.
When the Assassins Jacob and Evie Frye arrived in London in 1868, Kaylock's dominance over Whitechapel was threatened. With the emergence of a new gang, called the Rooks, Kaylock was forced to engage them in a gang war.
Foolishly self-confident, Kaylock put his train on the line during the gang war. When the twins killed all his men, Kaylock battled them on the roof of his moving train, but was killed when the Frye twins kicked him off the roof. After the Assassins killed him, they took possession of his broken grappling hook pistol and his train, turning the vehicle into their own base of operations, and adapting the grappling hook into their gauntlets.
- Kaylock is the only one of the seven gang leaders to wear a unique outfit, different from the standard Templar uniforms.