Caring for a Monster in Disguise

After a car accident leaves my girlfriend, Avery Moore, with brain damage and the mind of a young child, she becomes prone to violent outbursts and destructive behavior. My younger sister, Delilah Barnes, and I care for Avery around the clock. To pay for her treatment, Delilah drops out of school and works three jobs, exhausted to the point she can fall asleep standing up. One day, while trying to stop Avery from wandering into deep water, Delilah, who can't swim, accidentally falls into a fast-moving current. Avery, with her childlike mind, simply turns and walks away, never noticing Delilah being swallowed by the river. I believe it's nothing more than a tragic accident. Until the day of Delilah's funeral, I overhear Avery on the phone. "He passed the test. Even though he came with that burden of a sister, he's been genuinely devoted to me. Now that his sister is dead, he'll have no one else. For the rest of his life, he'll depend on me and devote himself wholeheartedly to being my husband." It turns out Avery has been faking her mental decline to test my love for her. At that moment, my heart shatters beneath her feet. Avery Moore, I've passed your test. But now, I don't want you anymore.