Goes off-canon during The Harsh Light of Day. Sunnydale is devastated by the release of a prototype virus that was being developed by a branch of The Initiative. Now, half the population is 'infected', and the other half is living on borrowed time. A bite will turn you into one of them, and Buffy's got her mom and sister to think about. With the gem, Spike's immune and so it makes perfect sense to Buffy that he should help them get out of town. But this thing's already bigger than Sunnydale, and if Spike's their best chance of survival then it looks like he's along for the ride.
 

Introducing: A vampire who's been needed before, but never exactly wanted. And a girl struggling to understand the true nature of good and evil, whilst standing shoulder to shoulder with the Slayer of Slayers. (Inspired by Stephen King's The Stand, AMC's The Walking Dead and every zombie flick I've ever set eyes on).
 

Winner at the SunnyD Awards (Round 31) for Best Unfinished, Best Drama and Best Plot. Endless heartfelt thanks to everyone who voted!
 

A response to Loup Noir’s Challenge.
“It doesn’t matter. If Dawn dies, I’m done with it, I’m quitting.” What if quitting wasn’t all Buffy promised?
Despite Glory’s defeat, the portal was opened. The Scooby gang sacrifice Dawn to save the world and spare Buffy the pain of having to kill her own sister. Vanishing after the battle, Buffy and Spike go into self-imposed exile for 147 days. Bereft of family and duty, Buffy the Vampire Slayer ceases to exist and is transformed into Dusk, the Slayer of All. Spike remains by her side, dedicating himself eternally and unswervingly to her cause of vengeance.
On the 148th day, the end begins. An apocalypse unlike any other is brought to town, and this time, the Slayer fights for the dark. The Scooby gang quickly learn the deeper meaning of ‘Better the devil you know…”
Thanks to Axell for the incredible banner!