"After having that fight with my mother, she finally threw the car keys at me. She said "if you really want to leave, you can. These are the keys to your freedom. But just know you are breaking my heart." I took the keys, and holding them in my hand, I looked at them. She was right. The keys represented my freedom. They would allow me to leave this place and never look back. However, they would also close the door between my mother and me forever. I didn't know what to do..."
In this passage, the keys are used as a symbol for the freedom that the speaker is looking for. The keys are both "a way out" for the speaker, as well as a way to leave her family behind. The suspense is created by the fact that the reader does not know whether the speaker will stay or leave.
