A foster-care placement, no matter where or when, can be a difficult, even traumatic transition for all parties involved. Much can go awry, especially when children expect that their parent or parents will return for them. Alex Howarth, writer and director of Cassie and the Lights, draws the audience almost vicariously into the fantasy-filled and emotion-and-guilt-fraught world of three sisters in foster care in northern England. Their strongest, and possibly only, tool for survival is their bond with one another.