First, this is not an Assassin's Creed crossover. If you want to read an Assassin's Creed crossover, go looking for one somewhere else. Please.

The CMC are fed up. For five years they've been trying to get their cutie marks and for five years they've been failing. They conclude that the problem is Ponyville. They can't get their cutie marks because they aren't destined to get them in a profession that's found in Ponyville. So they decide to leave and try to get them somewhere else. Little do they know that their choice will rope them into a chaotic web of lies, spies and assassins, ponies who will do anything to keep a secret so big it concerns the entire world, and a organization that desperately needs their help to uncover a conspiracy dating back to the founding of Equestria. How will they handle it? Come on. These are the Cutie Mark Crusaders we're talking about here. The result will be pure chaos.

Rated T for violence in later chapters. Other than that, it's E.