Buffy the Vampire Slayer:
Buffy turns 18. As is traditional, on the Slayer's 18th birthday, without her knowing, she is drugged (to take away her slayer strength) and tested to see if she is good enough to remain as the slayer.
Dominic's character arc :
Blair joins Quentin Travers (head of the watcher's council) to Sunnydale in order to test Buffy. They bring with them a Hannibal Lector like Vampire (in a box, wearing a straight jacket) but Blair is tricked by him while giving him pills for a headache and is turned into a Vampire. Blair then joins Zachary's (the vamp in a box) fight against Buffy (and later, Giles) until, well... until the end.