Several centuries in the future an immortal Xander is 'haunted' by Buffy who is his eternal companion and guide. They are sent on a quest to regain that which is lost. He is given a slayer to help and he must, as always, protect the Key.
You decide on the following:
- The future AU is set in: Chronicles of Riddick verse, Firefly verse, or Star Trek verse. (or another as long as it has advanced tech & the ability to travel to other planets.)
- Xander can not die because: he is a 'Highlander' style immortal, he is a Marvel style 'external', a Naquada powered cyborg...