Dinky ends up getting tutored in remedial reading, since she has to learn how to read again. She takes it with as much grace as possible for the total rat bastard that she is. She also makes friends with a few ponies, including a quiet filly named Ruby Pinch. Then one day, Ruby Pinch shows up in Dinky’s class, having completely forgotten how to read... among other things. 

Dinky flips out, because it’s obvious what happened, and because the same thing that stole her memories went after her friend, and could still be happening to ponies. Twi’s in the library now, so Dinky accosts her and swooces her into helping so fast that Twilight can’t believe this foal is taking remedial classes. Basically blows the whole secret she’s been keeping wide open so that they can stop it from hurting others.

Still totally convinced that she’s the victim of memory loss, not a guy possessing a little filly.