Discord Plays a Game (Idea Fragment)

Based on a philosophy thing.

Discord gives Twilight a gift at her birthday party. He shows an area outside with two boxes; one opaque and another transparent with a book in it. He tells her the book in the transparent box is one she's been sending weeks looking for and seems to be checked out in every library in Equestria. The other box he says might contain one of Starswirl's personal journals—if he predicted she would take only the opaque box. She can take both. The transparent box, along with the book inside, will be incinerated when she leaves the area if she doesn't take it with her. The opaque box already either has the book in it or doesn't. He then tells her he used to do this sort of thing every year for a random pony in Equestria when he ruled it and never once made a wrong prediction. Then he leaves saying he has things to do. Twilight deliberates what to do, and Rainbow Dash says it's obvious, just take the opaque box and leave the other one. She wants the Starswirl's one more, right? She says it's not that simple: there is *already* either a Starswirl journal, or no journal. Not sure about ending.