It's the run up to the 1983 General Election and pressure is mounting on DCI Gene Hunt and his team as they investigate a series of politically motivated arson attacks. A fire at an army barracks is soon followed by another more serious blaze at a Polling Station. As CID turn up to investigate, a quiet word from DCI Jim Keats in DI Ray Carling's ear leads to the detective risking his life by running into the burning building to save a cleaner who is trapped. However, Ray's heroic intentions are short-lived as he is soon trapped too. Fireman Andy Smith saves the pair and the usually macho Ray is overcome with gratitude. As the arson investigation continues, Ray is devastated when an eye-witness identifies Andy as their prime suspect. As the team work on the case they discover that Andy is an army veteran who served in the Falklands; a war that changed him beyond recognition. However, when another fire with the same MO happens whilst Andy is still in police custody, Gene has no choice but to let him go - despite not being a hundred percent convinced of his innocence. Meanwhile, DI Alex Drake is still being haunted by the police officer with the 6-6-20 epaulette numbers and is struggling to work out why he keeps visiting her.