Jack Lithgow returns to Britain from Pakistan to find that his daughter, Caroline, has been arrested on heroin charges after a student party. Jack confines her to the family home and watches her night and day until he thinks she's off the drugs - but Caroline has been fooling him.

Back in Germany, Helen learns that her husband, Karl, is still owed a lot of money by his dealers, which she sets out to recover, but in a massive police raid Karl's entire network is arrested. The situation seems hopeless; Karl is formally charged with trafficking and a trial date is set. Any chance of recovering the money has now been lost.

In Pakistan, Fazal travels to Karachi in search of work and becomes increasingly involved in the heroin empire of Tariq Bhut, a wealthy and influential drug trafficker.