Either Cassian's brain was really misfiring—perhaps he was under the influence of something…? but no other symptoms noticeable…

—or Kay was referring to what Cassian thought he was referring to. In which case…

Maybe the head injury he'd sustained being shot off the tower had gone far beyond his self-diagnosed concussion. Otherwise, nothing made the least banthaspewing sense.

"I thought you hadn't," he said quietly. His hand came up to clasp Kay's forearm. "Outside the data vault… you said goodbye."