Eternal Life by Eternal Death
Buffy was walking through the cemetery on patrol when a vampire attacked her from behind. She flung him over her shoulder where he landed face down. "And here I thought the cemetery was gonna be dead tonight." Pulling the stake out of her jacket, she attempted to plunge it into the demon's heart, when it flipped up, kicking her in the stomach. She groaned as much from pain as surprise when she saw her attacker's features. "Giles…oh no…" but she remembered she saw Giles just before she headed out to patrol. Even if Giles was bitten after she left, he wouldn't rise until tomorrow. She looked at the vampire with the face of one she considered family and said to the vampire, "So you can't be Giles, and that means to get to die…again." Before she could dust the Giles look-a-like, Angel tackled her from behind.
"Buffy, you can't kill him," she heard Angel say. They both got up from the ground and watched the vampire run away. Buffy glared at him and started yelling. "First, why does everyone keep attacking me from behind! Second, I just bought this outfit! Third, why the hell not! Killing vamps is part of the job description remember!" Buffy was now restraining her from punching Angel.
"Well, yeah, he's a vampire, but…" realizing he could never explain everything that was happening, resumed. "Just go talk to Giles. He can explain everything."
"Alright we've established that wasn't Giles, so who was it?"
"Well…that was his twin brother."