The Wood Beyond

The episode runs two stories, one in the First World War and one in the present, and cuts between them. The older strand opens on the wedding day of Pascoe's grandparents. Pascoe's grandmother is pregnant and his grandfather, Robert Pascoe, is going to the war. He is a stretcher bearer, and he comes to suspect a medical officer of deliberately killing wounded men by injection. The officer's project is to find the doses at which an arsenic compound can be turned into a working antibacterial solution, and his patients are his test material. Pascoe's grandfather is wounded and sent back to a military hospital in Yorkshire, where he meets the same officer again. He then disappears. According to the official record he deserted: his uniform was found on the docks at Liverpool and he was presumed to have sailed for America. Pascoe's grandmother never believed it.

In the present, a group of animal rights activists raid a pharmaceutical research facility. They release research animals and do serious damage. Their leader is Amanda Marvell. While the others free the animals she copies data from the company's computer, and then escapes into the woods beyond the site, where she falls and discovers a set of human bones. Dalziel and Wield investigate the raid, and the raid has become a murder inquiry. Dalziel is attracted to Marvell and investigates her at the same time. One of her followers is murdered, and Marvell's own vehicle is part of the evidence.

Pascoe, as executor of his grandmother Ada's estate, has found his grandfather's letters from 1915 and has begun reading them, and the episode plays the letters as flashbacks. He works on the family history while the police work the bones. The bones are found to contain arsenic. Marvell's brother is found to have died in Africa in circumstances that are not accidental. Dalziel finds that experimental data has been stolen from the laboratory, which shows that the company's work in Africa was not the purely medical mission it claims to be. The two chains of evidence bring the detectives to the point where Pascoe can show that his grandfather was innocent of the desertion with which the record charges him.

The account of the officer's identity and method is a reported claim from a fan-maintained source rather than a verified one. That account gives the officer as Captain Herbert Batty, says he experimented on the wounded under his care with arsenic compounds at the cost of at least twenty-three lives, that he had himself posted back to Yorkshire where he took over his own former family estate, by then a military hospital, that he continued the experiments there, disposed of the surplus bodies in the woods, murdered Robert Pascoe and then framed him for desertion. What is verifiable is narrower: the television cast credits Herbert Batty, and two further Battys, Arthur and David, which is consistent with a family company or a family connection running through the story. Named sources do not establish the present-day resolution either, so who killed Marvell's follower and what becomes of the laboratory plot are not recorded here.

The episode is the last of Series 3 and the fourth of the four stories. Its structure is the most ambitious in the early run: a single inquiry in two periods, joined by a family relationship rather than by a shared culprit, with the letters as the mechanism for moving between them. The wartime material gives the series its only sustained historical sequence, and the estate and hospital setting is the visual counterweight to the Yorkshire of the present-day strand.

Colin Buchanan's Pascoe carries the story's emotional weight, because the family history is his and the case he is working turns out to be about his own grandfather. The episode is the point at which the series gives Pascoe a private stake in an investigation rather than a domestic complication alongside one, which is a departure from the pattern the earlier stories set. It also marks the end of the run's first phase: after this, Series 4 opens in June 1999 with the whole standing cast in place and no further adaptations of the early novels in the run.