Lily Emmett prefers to stay silent. Having suffered from selective mutism since childhood, she struggles to see the value of everyday speech. Her partner has learnt to speak for her and they share a unique form of communication. But when Lily and her sister Connie return to their childhood home, the visit inspires memories of the event that first rendered Lily silent. The search for the truth about what happened takes them back to a childhood shaped by bullying and breakdown, unearthing the secrets that lie at the heart of their relationship.