Supernatural: Heart (2007)
Air Date: March 22nd,
Episode: Season 2, Episode 17
Summary: Sam and
Dean investigate a series of murders of a werewolf where the
victims have their hearts removed. When a lawyer is killed
in his office, the Winchester brothers visit his assistant
Madison and they believe her former boyfriend Glen is the killer.
Sam stays in Madison's apartment to protect her and they fall
in love for each other while Dean investigates Glen; however,
they discover that Madison is actually the monster and they
give their best efforts trying to save her from her fate.