Her tact is a blessing. Mycroft blinks slowly and allows the subject change to distract him, the sound of Vanessza's voice like a guiding hand.

“The last one...” he says, beginning to reanimate with interest. “I'd heard talk of other worlds like this. I suppose previous experience must make it all a bit... easier to accept, yes.”

His agreement carries undertones of both doubt and curiosity; his voice has quieted and softened around the edges by a small degree. Out of misplaced reflex, he doesn't mention her time-related error.