( Istredd is a solid person to lean against and in case Jack doesn't entirely remember the twists and turns of the castle, he knows exactly where Sabine has been staying so he knows where to go with confidence. He figures expedience means more than pride at this point and he firmly helps Jack move along.

Well that doesn't bode well for Sabine's future, so he finds himself very glad that she's here now and safe from whatever that is, just like Lucifer. He figures Jack's mind is still struggling with all the information, so he is patient as he explains.)

This place is outside of time and space from your sphere, people can be here when they aren't back home. She was plucked out of an exact time and she is safe here.

( Until something happens or she goes back, but that isn't of importance right now. Whatever time Jack and Sabine get to share now, it might be borrowed, but it'll hopefully be enough.)

She's alive and well, Jack, and she'll be glad to see you. As much as we try, Kyle and I aren't better company for her.

( A little bit of dry humor there too, but they have tried to keep Sabine company since Jack's disappearance.)