John Amherst is an avatar of The Corruption. He spreads disease to people and seemingly even objects around him, and has an affinity for insects (particularly ants and flies). He has a unique form of immortality for an avatar; though he can be killed, he simply returns to life soon afterwards, apparently no worse for wear.
He is described by Nicole Baxter as being very thin, with watery blue eyes, unruly upright dark hair, and a "nervous energy", appearing to be around the age of forty and wearing a brown suit that is too large for him (MAG 36). Jordan Kennedy refers to Amherst as "tall, maybe six-and-a-half feet." (MAG 55)
The supernatural version of the book The Tale of a Field Hospital contains alternate chapters not present in the published version that feature a Private Amherst. He is a soldier in the Second Boer War who is constantly surrounded by flies, repeatedly dies of various diseases and infections, and seems to spread them to others.
Jonathan Sims speculates that given the age of the book, this may be an ancestor of John Amherst, but given his many deaths, possibly the same man. Sir Frederick Treves, the narrator of the book, also mentions the name shared with Jeffrey Amherst, who was known for using smallpox blankets as biological warfare during the French-Indian War, which John notes as "a connection to a very different sort of monster, but still one that has the trappings of disease." (MAG 68)
Jordan Kennedy, an exterminator, is called to an ant-infested house in Bromley by a concerned neighbour. Amherst, apparently the owner of the house, shows up and attempts to strangle Kennedy, who holds a lighter to Amherst's arm in self-defence. Amherst ignites very quickly, and the burning smells like "sun-cured roadkill, stale sweat, and rotten eggs, with just a hint of burning rubber" with an underlying smell of sickness - which Kennedy notes is the same as the smell of the "wasp's nest" in Jane Prentiss' attic being burnt, as well as when Jane herself (another avatar of the Corruption) was cremated (MAG 55).
Either just before or just after this event, Amherst becomes the new director of Ivy Meadows Care Home in Woodley. A nurse phones funeral directors Nicole and Josh Baxter in order to remove the body of a resident who had passed away, and they discover that he had become infected with a creamy yellow rash infested with flies. Amherst arranges for the resident's ashes to be returned to Ivy Meadows, a request which is not granted. Two weeks later the nurse phones again, and Nicole Baxter returns to find the entire building to be disturbingly diseased. After Baxter leaves, the care home is burnt to the ground by Julia Montauk and Trevor Herbert. (MAG 36)
Amherst has taken over the small German town of Klanxbüll. It is unclear whether he is attempting a full-scale ritual or afflicting only the town. He has infected the residents with an illness that causes the skin and muscles to become loose and malleable until they slough off the body, leaving the skeleton and organs exposed. He also exerts some form of control upon the infected residents, directing them to form a throne from their rotting, but still-living, bodies.
Adelard Dekker arrives, catching him off-guard, and they fight. Amherst opens a cut on the leg of Dekker's biohazard suit, infecting him with the disease, but Dekker, in turn, injects Amherst with pesticide, incapacitating him temporarily. Dekker ties him to a stretcher with quarantine sleeves before throwing him into a hole and entombing him in wet concrete, a simple solution to Amherst’s immortality.
In MAG 184, Jonathan Sims states that after being buried in concrete, Amherst became starved of fear and shrivelled away.
John Amherst has appeared in the following episodes.
- Writer Jonny Sims has stated that, despite sharing a last name, John Amherst was not deliberately based on the historical figure Jeffery Amherst.