"Well." Watson takes a breath. "What I have been told is that there is some sort of energy to found in souls, and that we are a source of it. A sort of battery, if you will, for the Captain. How or why is something I cannot answer, but..." He shrugs. "I cannot say how plausible that theory is, but it was presented to me by, ah, let's call her an alumni of this place who came back to visit us briefly."