At first Sina doesn't know what Gwen means, and she turns to look at her quizzically. Then the detail about the rift is added, and she understands. Although her expression doesn't overtly change, something about it becomes ...somehow older, thinner, more tired.

"It opened above me," she answers quietly, "...I... think around the time the Breach did." She has no proof of that, but based on how long it took her to get here, the timing seems right.