The Ending is Nonsensical
Justify tells Jill that Violet & Ben left Caroline the house in their wills. Great, only Violet & Ben aren't dead. They are being taken away in an ambulance to a hospital where they will recover. The story established the fact that unless the 'medicine' continues to be given the person begins to regain functionality. After missing one dose 'Ben' was able to write and make an escape attempt. So assuming that either is smart enough not to get committed ranting about hoodoo, they are just going to write new wills and then show up with the police and kick the lawyer and nurse out of their house. Then they will have possession of all Justify's spells and can seek a remedy.
Or they could just show up with a gun and shoot them both. The whole let them live & leave makes zero sense.