Cat Scan (Los Diablos, California)

Detective Delacroix has a complicated life. Unable use magic, other than detect it, he works for the Los Diablos California Police Department in the magical crimes against person unit.
An ancient amulet that has been stolen by a (literal) clown. It gives the holder the ability to control minds, but houses a terrifying entity. Delacroix barely survives retrieving it.
Then it gets weird.
Some one or some thing known only as "The McConnel" wants the amulet and is willing to massacre thousands to get it.
Delacroix’s only hope is help from a select order of monks, a four thousand year old virgin, a talking cat, a bevy of swans, some combat demonologists, a quantum mechanic, a problematic girlfriend and a more problematic partner.