Agent Sparkle was a logical, scientific mare, firmly grounded within the realms of the real world.
Agent Pie was a renegade, believing in things most other ponies would call her insane for even thinking of.

Now they've been assigned together, to work on the so called 'S Files' of the EBI. They can trust nopony as they delve into the vaults of horror and strangeness that lurks just beneath the surface of calm, beautiful Equestria.