As the threat of witch hunters circles the Institute, a mysterious illness begins to affect the Institute's monsters, and a long-disappeared frenemy reappears with intentions unknown. One thing is clear: they're here to stir up even more trouble among the local monsters-in-residence, and it seems like it's working on everyone.
Persie finds herself at the epicenter of a brewing war quickly approaching its boiling point-and all her friends, enemies, and we'll-find-outs are headed for a collision.