When reality turns to fantasy. And fantasy turns to terror...

Greg Sanderson is helping his wife, Jan, to recover from a nervous breakdown and revive their strained marriage. Their privacy is interrupted by the arrival of Greg's stunning and mysterious sister, Laura. Jan's paranoia deepens as she suspects that Greg's and her sister's relationship is too close. In her desperation, she confides her fears to the landlord but his weird reaction only creates more confusion.