A little more than one year ago, Albert and Brandy discovered a fantastic labyrinth hidden deep beneath the streets of Briar Hills, Missouri. Now, strange telephone messages are stirring up the memories of those dark passages, and it seems that it may be time for them to return to that perilous, underground world to finish what they started. But when a strange envelope is given to him by a girl named Andrea, Albert finds that he is being steered not toward the university’s steam tunnels, where he began his last journey, but to the bizarre ruins of Gilbert House in the woods north of the campus.
Together with Brandy and her best friend, Nicole, Albert ventures into the forest in search of answers. There, amid the crumbling walls and overgrown brush, they encounter Wayne, another local student who was also lured to these ruins by a mysterious envelope. Banding together, the four of them descend into the recently opened cellar door and discover the nightmarish secrets that have long been hidden within the terrible hallways of Gilbert House.