Princess Twilight Sparkle, in her exploration of the Royal Canterlotian Library, discovers an ancient spell that allows two ponies to combine into a single, unified pony. Doing her research, Twilight Sparkle thinks that she has improved upon the spell, and rather than two ponies sharing one body, it's one pony with two sets of memories.

With the help of her friends, she's going to discover that being more than one pony is an adventure in the making.

NOTE: Tagged mature for implied and actual sexual content, full contact shipping, slight gore, some violence, psychological nudity, cupcakes, bad jokes, and the existance of a spell that somehow allows Pinkie Pie to become an alicorn.