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Warning - spoilers for the current Dr. Who series.
Don't They Know It's The End of the World?
Spike was bored until he noticed the police box and smelled its returning occupants. The man wasn't human, not demon... alien? Spike slipped inside with vampiric speed, and hid in the shadows as they talked about time travel.
Eventually they arrived somewhere; Spike stole some trinkets then followed them into some sort of space station. The door clicked shut. Outside the sun was shining, a huge exploding monster, but he felt nothing; must be necro-tempered glass. Below the Earth was burning.
"WARNING. SHIELD FAILURE." Spike was still hammering on the TARDIS door when the unfiltered rays reduced him to dust.
Other people have also done the sunlight thing, but I think that I've found a different way to get Spike there...