Angels in the Machine

"Angels aren't real. They can't be." More than one hundred years ago, a man was found dead in a London church. At the time, eyewitnesses claimed to have spotted an angel in the vicinity. The idea of a murderous angel was quickly dismissed, and the case was largely forgotten. Until it happens again. In the same church. Today. Robinson is certain that angels aren't real, but he also knows that something is definitely behind the killings. And when more reports come in of angels in London, he begins to suspect that someone somewhere in the city might have revived an old experiment that was once buried due to its horrific results. Have angels come down to the streets of London, ready to commit horrific murders? Or has something even more terrible been created in a top secret laboratory?