Once Upon a Time... This Morning(1995)

Original title: กาลครั้งหนึ่งเมื่อเช้านี้

A middle-class couple are separating and the three kids are to stay with their bossy and resentful mother. Missing their beloved father, the kids run away to look for him – unaware that the baby's carry-cot contains a bag of pure heroin hidden by a street-kid during a police raid.