As centuries pass, monuments crumble and legends distort, so Princess Celestia gives each of Equestria's greatest champions one chance to set the record straight. She allows them to choose a single memory, and she stores it in a magical crystal in an annex of the Canterlot archives, viewable by anypony who wishes to learn of past heroes.

To honor her many years of heroism, Pinkie Pie has earned the right to store a memory. But which of her memories is most important?