If Dogs Run Free

The first in the final two-part episode in the series sees Frost attempting to crack an illegal dog-fighting ring, only to discover that its manager, a wealthy Denton businessman, has links to a drug-smuggling operation. Frost also begins to form a relationship with RSPCA Inspector Christine Moorhead, and attempts to finally get over the death of his wife. Frost considers retiring from the Police force and plans to get married, ending the series, however DS George Toolan dies of heart failure following a collision outside the church where the wedding is about to take place. It is noteworthy that three alternate endings were filmed, where Frost, Toolan or Mullet die of heart failure in hospital. David Jason chose the 'happier' ending and weds his new love Christine Moorhead.