The mimic in Wade's voice made him smirk, but it was her professor's chosen subjects that made his eyes alight with interest. Listening closely while he was tramping through the undergrowth, he pointed out a large, gnarled root to avoid. With Wade's pause however, he looks back over his shoulder again and from her explanation, surprise and a little shock indeed registers on his face.

"I beg your pardon? I thought you just said parallel universes?"

Knee deep in foliage the Doctor came to a stop.

"Event One and particle physics, metaphysics and the nature of being. I think I like your professor already but I might be able to put some of his ideas on their head. Namely, travel to parallel universes in your time isn't possible. It shouldn't be possible. The technology alone is so far advanced... What time are you from?"