Some ponies think Diamond Dogs hoard gemstones for the same reasons ponies do. Others think they eat them, like dragons. If ponies knew the truth, they might not be so eager to rob them of their subterranean treasure. If only they knew.
Everypony has their secrets. Twilight never imagined those her own best friends might be hiding from her, until one of her new duties as a princess brought her stumbling headlong into a side of Equestria she never even knew existed.
When a remarkable spell summons a human mind into the body of a unicorn filly, Princess Twilight Sparkle does the only thing she can think of: Take on an apprentice.
Humanity's space exploration ultimately took the form of billions of identical probes, capable of building anything (including astronauts themselves) upon arrival at their destinations. One lands in Equestria. Things go downhill from there.
