David Osborne is a successful advertising executive who seems to be living the perfect life with his wife, Cassie, and daughter, Samantha. However, their marriage is strained due to David's constant work and neglect of his family. One night, after a heated argument, Cassie takes Samantha and leaves for her sister's house.
On the way, their car breaks down and they are picked up by the Scudders, who seem friendly at first. But when they arrive at the Scudder's home, Cassie and Samantha soon realize that they are being held captive.
The Scudders are a wealthy and reclusive family with a strange and twisted past, and they believe that Cassie and Samantha are the key to their redemption. They refuse to let them leave, and Cassie soon realizes that they have been drugged and hypnotized.
Meanwhile, David begins to search for his family and is aided by Joanne, Cassie's sister, and a private investigator. As they investigate the Scudder family's history, they uncover a dark and disturbing truth.
The Maddening is a suspenseful and chilling thriller that builds towards a terrifying climax as Cassie and Samantha fight for their lives and David races against time to save them.