After leaving Melbourne to head up a medical service in South East Asia, Lloyd Prentice vanishes without trace. Four years later his young adult son and daughter, elated by news that he is still alive, fly out to join him in Thailand—only to find themselves alone and facing unknown dangers in the hot, teeming city of Bangkok. Soon propelled into an Asian underworld, Joshua and Julia draw upon unknown reserves of courage in a desperate bid to find their father. But what they uncover is terrible. Could all their cleverness and daring be to no avail? And what dreadful culmination might be awaiting them?