Jack's eyes narrowed as the woman came closer. She'd claimed some connection to Ianto, but he was rather certain he'd never seen her before. Which meant either she was from another reality, or lying, and at the moment he was edging towards the latter.
He levered out of his corner, fingers closed around the smooth metal of one of the lamps - broken, as everything else was in this strange room - that had been nearest him.
"Don't," he said flatly, his expression hostile, his body tensed for a fight.