Applejack finds a strange visitor in her apple orchard one day, with even stranger stories to tell...
MLP/L4D2 crossover. My first story on FiMfiction.net! May add more tags as story progresses.
Credit for the image goes to brokencreation on DeviantArt.

Humans.

Truth or myth? Ancient lost civilization or just an old pony's tale?

No pony has ever seen one, and most haven't even heard of them. But Lyra knows that these wonderful creatures are more than just old legends, and she's going to find out... and possibly drive her roommate insane in the process.

Pinkie Pie is visited by a strange customer whilst working at Sugarcube Corner. Hilarity ensues.

In the 31st Century, humankind has spread to thousands of planets in the Inner Sphere. Once united under the glorious banner of the Star League, the Successor States and their noble houses now fight bitter wars over the scraps of empire. When a JumpShip carrying a special task force from the Federated Suns suffers a catastrophic misjump, the occupants find themselves stranded above a strange, beautiful world at once alien and eerily familiar.

Meanwhile, in the peaceful realm of Equestria, Ponyville’s resident bookworm , Twilight Sparkle, has stumbled upon hints of a secret buried for centuries. A secret that may lay bare long-forgotten aspects of Pony history and culture.

Our story begins on the planet Valexa, where the beleaguered Militia has launched a last-ditch effort to call for help against overwhelming odds.

Written with those who are not familiar with the BattleTech/MechWarrior universe in mind.