Discord's been settling in, if you can call anything Discord does "settling", to life as Fluttershy's housemate. He's friends now with both Fluttershy and Pinkie Pie, he's become an extraordinarily annoying second mentor for Twilight, he and Celestia are even making attempts to repair their old friendship. But what comes as close as Discord can get to "ordinary" life is haunted by a secret he's not willing to share with any of his new friends. He's been exiled from the Q Continuum because he's on trial. And there's a very significant chance they're going to take his powers away.
This is what happens immediately prior to and during the TNG episode "Deja Q" from the perspective of Discord's pony friends. Or, why would someone take refuge with "the closest thing" they have to a friend when they have actual friends they could go to instead?