Karl turns into the very thing the experiment wanted to prevent, a vivious predatory animal.

Love's Labor's Not Lost, my favorite episode

Murdoch is haunted by his lost love. My favorite epsiode

Marty gets the "Stirring" an affliction resulting when the first moon rays in the fourth quarter touches the coffin of a Vampire, resulting in Marty regressing to the primal urges of being a Vampire the very thing the experiment wants to prevent

Karl suffers what the Vampire's would call the "Chill", when a Vampire gets the urge to return to his former life.

This is what I would call a perfect teacher

A group of young vampires are brought to a boarding school so they can be integrated into human society. Drew, a vampire, forms a psychic bond with Sherry, a human.