Dr. Saunders and I are from a reality where a pharma company called Rossum developed a technology to take people out of their own brains and program them with a new one. It's a long story, but I have more than one -- over fifty, actually -- and there's something special in my spine that helps me control them and keep me from ... what you saw a few days ago. Whatever changed us must have messed with my spinal fluid.
The extra brains are called imprints and sometimes the wires get a little crossed. Usually it just means a headache.