The Descent 3 is a 2014 slasher horror film starring Katie Cassidy, Emma Watson, Jeremy Irvine, Rooney Mara, and others.
Carmen Moore (Emma Watson) has a passion for caving. It was something that she grew up with. Along with her friends from her Outdoor Rec class, they leave on a final class field trip to begin exploring the cave. It isn't long before a cave in stops them in their tracks, with no way to turn back, they continue to push forward. Eager to please their good looking teacher, Carmen's classmate, Beverley Crew (Katie Cassidy) forges on ahead, and falls down a chute into a mass underground lake.
Desperate to save their classmate, the six members on the trip, including their teacher, brainstorm an idea to help their classmate screaming below. Gregory Dancy (Jeremy Irvine), Carmen's boyfriend, offers to drop down on a rope and help Beverley Crew out of the lake. As Gregory is lowered down on a rope to rescue their fallen classmate, Carmen starts to hear movement behind the group, and looks over her shoulder. Thinking she sees something, she alerts her best friend, Anna Blith (Rooney Mara), who says she doesn't see anything.
Once Gregory reaches the bottom of the drop, and is held above the water, he desperately looks around for Beverely, who he can't see. He notices a light, from what he's assuming is her headlamp, just off a few feet on a small land area. Believing that Beverley swam to the small area to get out of the water, he calls up to his class that he's unhooking the carabiner. Just as he's about to, a Crawler jumps from the water, and rips out Gregory's throats.
Alerted by the screams below, the class begins to pull Gregory back up to the upper section of the cave. Once his body comes into view, completely mangeled, the rest of the class begins to scream, and a Crawler drops down from the roof, killing their teacher. The remaining classmates scatter.
Carmen, having the right sense of mind, quickly gathers her fallen teacher's backpack from the ground before taking off in the opposite direction of most of her classmates. Lost in the cave system, most of Carmen's classmates are picked off one by one as they try and find a way to escape.
Carmen uses a rough copy of a hand drawn map that her teacher had acquired from the police investigation. Using this map, Carmen manages to find a broken down elevator shaft, that no longer works. Hearing screams behind her, she takes off again, this time falling down a steep slope into the den of the Crawlers.
Emma Watson as Carmen June
Katie Cassidy as Beverley Crew
Jeremy Irvine as Gregory Dancy
Rooney Mara as Anna Blith
Ryan Reynolds as Bob
Carmen Moore, Anna Blith, Bob
Anna and Carmen are ambushed by an old man who refers to the Crawlers as 'his children'. Carmen escapes and stumbles out on to a road, where she is hit by an oncoming car. Later to wake up in the hospital.