This is How It Happened - Tapa blanda

Revenge is sweet... especially when it comes in the form of brownies laced with rat poison.

Maddy didn't actually want to kill her ex-fiancé, Carlton, she just wanted to scare him. Carlton took her heart, her career, her ideas, so it's only fair that she should take some sort of revenge. After ruling out death by chocolate brownie, cyanide-infused vodka and voodoo, Maddy decides to hit the caddish Carlton where it'll really hurt - his ego. But hiring a hit man to do it probably wasn't the best idea. Things are about to get dead serious...