Wrong place, wrong time or could a ten year girl be guilty of murder?

The Butterfly State is the story of a County Wicklow family whose lives are forever altered when their violent, alcoholic father is murdered by the lakeshore near their home.

Tess, his eleven year old autistic daughter is charged with the murder, having been found standing over the body with the murder weapon in her hand.

Tess is sent to an institution for ten years and her sibling's lives are equally ruined. Her sister's engagement is off. Her older brother sinks into alcoholism while her younger, more severely autistic brother is left in the reluctant care of the two older siblings.

Tess's return home opens old wounds and brings about a chain of events that reveals what really happened at the lake. Tess's return culminates in salvation for her sister while her brother spirals further into self destruction, believing that she is secretly planning his downfall.