One pony's dream of meeting a human leads them to making a pact with Discord, but like such things always do, this brings about consequences that none could have foreseen. A dangerous enemy is brought to Equestria, and its minions are more than willing to begin exploiting this new world.
Elite XCOM operatives will have to work with the inhabitants of Equestria and beyond if they want even the slightest hope of slaying their hated rivals, and more importantly, to get back home.