Just a Memory

A story about Pinky's origins. Pinky has an odd habit of pretending things are alive. Especially the spool he refers to as "Sis." What if it wasn't just a silly game in his head. What if, at one point, there WAS a Sis? Not just a sister, his twin sister, of course. Will Brain be able to piece together what's happening to is dearest friend? Eventual PxB.