The movie starts out with an American family who are staying in some East European Castle with their young son. He’s like maybe 9 or 10. I think it was in Czechoslovakia, maybe Romania. It’s night time and the boy is running around trying to escape some thing that is chasing him throughout the castle and you can hear his parents screaming. He manages to escape the castle, but his parents are killed by whatever was chasing him.
Years later he comes back with his girlfriend or fiancee and their going to stay at the same castle. Little by little, his behavior becomes eratic as he is slowly being possessed by whatever force lives in the castle. Eventually, he starts chasing his girl and is trying to kill her.
She eventually makes it down to some hidden area where the mummified remains of some prince is sitting on a throne. Suddenly, the prince gets up and starts shambling towards her. He’s moving really slow since it’s all practical effects. Turns out he’s the one who has been possessing the guy. The prince was young when he died, I think, and wanted the kid to stay with him. That’s why he got rid of the guys parents. So, she’s being chased by both of them.
In the end, she manages to get away and I think she ends up killing her boyfriend in order to escape. Then, the prince sits back on his throne and whispers “Stay,” over and over before it fades to black and the credits roll.
Hopefully, someone here has seen it. I honestly think I only saw it the one time, but that mummy prince starting to move freaked me out when I saw it as a kid!