Spike takes on a witch for Xander (unknown to him) Xander goes looking for Spike, through a forest. In to an underground temple. Black Marble and some sort of white Lilly.
Spike is held forever in living death, dessicated. Xander realises he must sacrifice his life for him and slits a wrist (?) passing out as his blood wakes Spike. Who turns him, which hurts A LOT as the demon makes its self at home.
Enough that some one can point me in the right direction? I even read all the Vamp!Xander descriptions at the Spander files and no luck.