Greta considers his question for a beat, then shrugs. "I don't know. This has only happened to me once before. The Rift?" That seems like a safe enough guess.

Anyway, the 'how' doesn't seem as important as what they're going to do with this information. "If it's your dream, maybe you can change it," she suggests, retrieving his shirt from the tub and handing it to him. "So we could go anywhere at all. We wouldn't just be limited to your usual places." Right? She honestly has no idea how this works, and her last dream experience didn't exactly strike her has malleable. But it hadn't seemed like her dream, either, whereas this time, it's clear enough who's in charge (so to speak).