"Acacia" stars Shim Hye-Jin and Kim Jin-Keun as a married couple unable to conceive a child. The husband is a doctor and the wife spends her time judging student of art and knitting. Things change when the couple adopts six-year-old Jin-Seong (Moon Woo-Bin), a quite boy obsessed with drawing pictures of an acacia tree that he believes is the reincarnation of his dead mother. The family goes through some rough patches, but eventually a semblance of happiness is achieved. That is, until Mi-Sook becomes pregnant, setting off a chain of events that ends disastrously when, one rainy night, Jin-Seong goes missing...