Early on in the movie, actor Nicolas Cage has awoken and is lying beside his refrigerator, and he feels his finger that is now missing a ring. In a flashback we see he is out on the binge, and visits a hooker who, while sucking his finger, removes the ring from it easily and keeps it in her mouth.
Later that day, we see him at work, and he is asked to see the boss. When he is seeing the boss we can clearly see the ring on his finger.