over the wall
Free after having escaped from prison. I'll go crazy in here before the end of my sentence—that's why I have to go over the wall! I'll try to pass your message to Cynthia once I'm over the wall.
*over the wall
reaching freedom from a prison. (*Typically: be ~; go ~.) Max tried to go over the wall, but they caught him. Lefty was over the wall for a week before that caught him.