A group of psychology students get lost on their way home during a hurricane, and are forced to take shelter in a mansion occupied by psychopaths.

First: You should cut…

“A group of psychology students get lost on their way home during a hurricane”

And change it to.

“After a group of Psychology students take shelter in a secluded mansion”
—–
Next: You should give the group a goal.

“After a group of psychology students take shelter in a secluded mansion they must battle the psychotic residents if they are to survive the night.”
—–
Finally: Any detail you can bring to the logline that will distinguish this story from any other– “Take shelter in a secluded mansion”– story would be great.

“After a group of psychology students take shelter in a secluded mansion, they must use there psychology skills on the psychotic residents if they are to survive the night.”

In other words, since they are Psychology students and they are stuck in a mansion occupied by psychopaths, instead of battling the residents maybe they survive by helping them become sane.

Psychopath: I’m gonna eat your brains!
Psychology student: Tell me about your mother? Did you have a good relationship?

(Alright that might be a little too out there, hehe)

Anyway, hope that helped, good luck with this!