Xander should not have been surprised. The second he let that information slip, he should have known that they would find a way to get to the others. That didn't keep them from retrieving Faith and Buffy and Kendra, even if Xander had a sneaking feeling that they would figure out how to if they kept him trapped in here for too long. What would happen then? How would he get them out of here if they lost his trust in him? How was he going to convince them to leave?
Xander didn't need to worry about those things. He couldn't now, not when he was standing face to face with a Jacen that, as he well knew, was not so pleased with what he had done. Why would he be? He had betrayed him. Thrown him to the dogs like a meaningless piece of meat.
It was for a good cause. Least it had been, so long as it didn't get screwed up.
"I suspect this is the part where you start asking the questions. Oh, Xander, how could you? Whyever did you do it?" He kept his fingers wrapped around the bars as he stared out at Jacen unflinchingly. Bring it, Solo.