A passenger airliner plummets into the Korean DMZ, killing every person on board but one: Susan Chin, a sixteen-year-old Singaporean girl with Down syndrome.

The authorities are quick to dismiss the crash as an accident, but the insurers aren't convinced, not over the girl's questionable account. 

Claims investigator Jean Wan is called upon to challenge the ruling.

She befriends Susan and uncovers an eccentric version of her story laced with magic mushrooms, a dead girl and the unusual bond between Susan and her father. 

Confronted by the stench of conspiracy, Jean realises she must strike at the heart of it all—the innocence of Susan Chin.