S4·E1 On Beulah Height

What happened to little Mary? Eight years ago, the town was sure they knew: Benny, a boy with a metal plate in his head, who also disappeared. When another little girl vanishes, the squad investigates, but Pascoe is sidelined by his daughter's meningitis. Mary's bereaved family adopted Betsy (now called Elizabeth), now a well-known singer, has come home to sing a requiem for Mary. Townspeople claim to have seen Benny; his aunt had a visitor asking about money close to her death; Betsy's fathers (birth and adopted) and even little Rose Pascoe are crucial witnesses.