The Doctor shot a look in her direction and frowned, before getting back to work. "I can't tell you what I don't know yet, I am formulating a theory, ideas..." he said. "Look, this TARDIS... it's on it's way, it's coming in fast and we don't know where it's from. I have a feeling that it's not from this universe. It doesn't feel right, there's something very wrong with Her, like she shouldn't be here" he explained as best he could, while working.