What the hysterical subject intensifies and overtly manifests is this lack of a certainty, the lack of an identifying signifier.
Hysteria is a discourse, and like every discourse it implies two partners.
In the hysterical discourse Lacan isolates one of the partners as the divided subject , the other as the master signifier, or the master who embodies it S 1 . The agent is what we call a place of power. In the analytical discourse, power is in the object commanding a certain task to the subject. What is important here is the identification of hysteria with the divided subject. Although you may easily illustrate this with any case of hysteria, I'd rather choose one which is certainly well known to you.