"But potentially risky. Miss Rose seemed to be under the impression that some manner of void is outside of that barrier. Even presuming for a moment that she is incorrect, can you prove the barrier is merely for restraint?" Eleanor gestures with her free hand, falling into an easy cadence of academic debate. "If one were to open a door on a submarine, or an airplane, for instance, disaster befalls. My own former home was many fathoms beneath the sea, and escape therefore no simple thing. Passage through whatever lies without, if indeed it is not suitable for life, must factor into the plan sooner rather than later."