She can try to promise? That is the most useless bubble wrap ever.
Clara made a face. Didn't their dimension have some sort of... coordinates? Or something? Maybe dimensions weren't supposed to know about others. If that was true? It meant that they were in a lot of trouble. The Doctor still had to get her back to the Maitlands.
The use of the word hadn't been lost on Clara. Actually, she purposely used the word. If their lives were nothing but leaves that fell off the trees, why not dimensions? She just hoped that no one had to sacrifice the leaves of possible days to stop whatever it was that caused the sky to break.