Master Curse from Magickal Attack by Gordon Winterfield. It has some pretty impressive effects.
That book is great to have on hand anyways as it helps use your anger to get through a number of problems, as well as letting that anger go while doing it.
It also has a great ritual in there to reveal line’s enemies, which might be more benefical as an alarm bell for others as you mentioned you wanted some of her coworkers to see how your target behaves.