-Spike and Xander are transported/travel somewhere (spell/ portal?), some sort of desert, very hot, nothing around for miles, to look for something
-Xander stops breathing a couple of times, at first Spike doesn't care but when it keeps happening and lasts longer he gets worried
-They get to a tent where an old woman? gives something to Xander to help him but Spike doesn't trust her
The next part I'm not sure if it's part of the same story or a different one
-They meet up with Angel who's also looking for the same thing
-All 3 of them hide in a cave, trying to escape from people/demons also after what they're looking for
I hope someone can make sense out of all that and knows the story.
Thanks in advance
EDIT: Thank you!! It was Ship of the Desert I was trying to find. The parts with Angel are apparently from another story.