Katie Ampersand is a soul trapped on the other side of causality, existing merely as a facet of consequence. Her relationship to causality is therefore one-sided. It is unknown how the world knows about her. It is unknown how people interact with her. It is impossible to contain Katie because in order to do that one must have already caused her to become contained without containing her in the first place. Furthermore, it is possible that her current state is a measure of containment applied by an unknown agent.
People interacting with Katie are known to sometimes hear the phrase we scream becaue we know why the caged bird sings repeatedly in their heads. Katie refuses to elaborate on the meaning of this sentence.