Season 1 Tvd

The tomb vampires, led by Anna (who wanted to save her mother), attack the founders. In the chaos:

As Stefan and Elena begin a tentative romance, strange things happen in Mystic Falls. A crow watches Elena. A fog rolls in. Attacks on civilians begin. Stefan realizes he is not the only vampire in town. season 1 tvd

Meanwhile, the Founder’s Council activates a plan to eliminate the town's vampires using a mysterious device. During the parade and firework display, the device is triggered. It emits a sound that incapacitates vampires. The tomb vampires, led by Anna (who wanted