Absolutely brilliant. The ending was just packed with emotion I wasn't sure right until the end which way you were going to jump. Them killing Buffy or Buffy saving them. The wanting friends back line was great.

The train metaphor worked wonderfully as well. And Xander's lines and argument was so cruel, cutting and so right. But I was so rooting for Buffy.

A yep Xander being caught out by the one thing he cannot control.

And like others said this begs for a sequel. Wonderful writing.