Prologue:

Revenge. Nowadays it is seen as one of the few things worth fighting for. The United States joined World War 2 with the intent of getting revenge for Pearl Harbor. They invaded Iraq and killed Osama Bin Laden as revenge for 9/11. Why? Because they couldn't forget those events. Vengeance is best served cold, but it still needs to be warm inside the heads of the vengeful. Humankind is well acquainted with revenge. However, they aren't the only ones. There are thousands of alien species living across the universe, and humankind is viewed by them as one of the most inept. Hell, even humankind has only had a few encounters with these alien species, and often they prove themselves our superiors. But what would happen if two, or three, or even four inhuman alien species, all with a thirst for revenge, were to cross paths? Let's just say, chaotic wouldn't be enough to describe it. And, as always, humankind would be somehow caught up in the mix.