The She Beast
(1966)

Transylvania in the 1800s: A young boy bursts into a church yelling that the witch has killed his friend.  The villagers say they can do nothing since they do not know where she hides. The boy saw her return to her cave.  The villagers follow him to kill her.  One man warns them to stop, because if they destroy the body without the proper rituals to destroy the spirit, it will be worse.  They ignore him and drown her in the lake.  As the witch is killed, she keeps repeating, "I'll be back here, I'll be back here."

Present day: Veronica and Philip are on an extended honeymoon driving through eastern Europe.  They stop in a dismal hotel. The creepy hotel owner peeps in their window as they get amorous.  Philip sees him, rushes out and beats him.  While they pack to leave, the hotel owner sabotages their car.  As they speed off, they lose steering and brakes and drive into the lake.  Philip comes up alone.  The rescuers pull up the car, but inside is the body of the witch, instead of Veronica.

Van Helsing informs Philip that his ancestors knew the witch would return.  They have handed down the responsibility of being prepared to stop the witch when she returns.  Somehow, Veronica's body in the lake has freed the witch.  The witch goes on a killing spree, to murder all the descendants of those who killed her 200 years ago.  Van Helsing and Philip manage to drug the witch, and take her back to the lake.  Van Helsing performs the correct rituals, and they dump the witch's body back in the lake.  Veronica surfaces, and she is still alive after a week under water.

His mission complete, Van Helsing asks if he can drive back to England with the couple.  As they drive, Van Helsing comments that it is hard to believe such beautiful countryside can hide such evil.  Philip states that it is a land of nightmares, and they will never come back.  Veronica begins to repeat, "I'll be back here, I'll be back here" , suggesting that maybe Van Helsing did not do the correct rituals after all.  

Thanks Joseph C!